Croatian geological heritage related to historical mining and quarrying

Exploitation of geo-resources has played an important role in the development of mankind. Hence, historical mining sites represent valuable industrial heritage. Unfortunately, it is not often recognised that outcrops opened by quarrying and mining, as well as ex situ collections of minerals, rocks or fossils found at such sites, represent precious geo-heritage. Historical mining sites in Croatia are not yet properly protected with the exception of two stone quarries. In this article, we present several mines and quarries recognised by locals as tourist sites which should be brought to the attention of the authorities responsible for geo-heritage protection. Preservation of geo-heritage in the frame of the mining heritage context is fundamental in promoting the proper protection, valorisation and utilisation of former mining sites as geo-tourism destinations.L'exploitation des ressources géologiques a joué un rôle important dans le développement de l’espèce humaine. C’est pourquoi les sites historiques miniers constituent un héritage industriel de valeur. Malheureusement, il n’est souvent pas fait cas des éléments affleurants mis à jour par les travaux de carrière ou miniers de même que les collections minéralogiques en musée, les roches ou fossiles sur place, qui représentent un précieux héritage géologique. Les sites miniers historiques en Croatie ne sont pas encore protégés, à l’exception de deux carrières de pierre. Dans cet article, nous décrivons plusieurs sites miniers et carrières, reconnus localement comme sites touristiques qui devraient éveiller l’attention des autorités en charge de la protection de l’héritage géologique. La préservation de cet héritage géologique dans le cadre du contexte d’un héritage minier est fondamentale en faisant la promotion d’une protection adaptée, de la valorisation et utilisation des anciens sites miniers en tant que destinations pour les touristes amateurs de géologie.La explotación de recursos geológicos ha jugado un importante papel en el desarrollo de la humanidad. Por tanto, los emplazamientos mineros históricos representan un valioso patrimonio industrial. Desgraciadamente, los afloramientos mineros y las colecciones de minerales y fósiles encontrados en dichos afloramientos no son normalmente reconocidos, sin embargo, representan un patrimonio geológico muy valioso. Los sitios mineros en Croacia no están adecuadamente protegidos a excepción de dos canteras de piedra. En este artículo, se presentan varias minas y canteras reconocidas por agentes locales como sitio turístico que debería ser tenido en consideración por las autoridades responsables del patrimonio geológico. La preservación del patrimonio geológico en el marco del patrimonio minero es fundamental para promover la protección, valorización y utilización de antiguos yacimientos mineros como destinos geo-turísticos

Croatian geological heritage related to historical mining and quarrying

Exploitation of geo-resources has played an important role in the development of mankind. Hence, historical mining sites represent valuable industrial heritage. Unfortunately, it is not often recognised that outcrops opened by quarrying and mining, as well as ex situ collections of minerals, rocks or fossils found at such sites, represent precious geo-heritage. Historical mining sites in Croatia are not yet properly protected with the exception of two stone quarries. In this article, we present several mines and quarries recognised by locals as tourist sites which should be brought to the attention of the authorities responsible for geo-heritage protection. Preservation of geo-heritage in the frame of the mining heritage context is fundamental in promoting the proper protection, valorisation and utilisation of former mining sites as geo-tourism destinations.L'exploitation des ressources géologiques a joué un rôle important dans le développement de l’espèce humaine. C’est pourquoi les sites historiques miniers constituent un héritage industriel de valeur. Malheureusement, il n’est souvent pas fait cas des éléments affleurants mis à jour par les travaux de carrière ou miniers de même que les collections minéralogiques en musée, les roches ou fossiles sur place, qui représentent un précieux héritage géologique. Les sites miniers historiques en Croatie ne sont pas encore protégés, à l’exception de deux carrières de pierre. Dans cet article, nous décrivons plusieurs sites miniers et carrières, reconnus localement comme sites touristiques qui devraient éveiller l’attention des autorités en charge de la protection de l’héritage géologique. La préservation de cet héritage géologique dans le cadre du contexte d’un héritage minier est fondamentale en faisant la promotion d’une protection adaptée, de la valorisation et utilisation des anciens sites miniers en tant que destinations pour les touristes amateurs de géologie.La explotación de recursos geológicos ha jugado un importante papel en el desarrollo de la humanidad. Por tanto, los emplazamientos mineros históricos representan un valioso patrimonio industrial. Desgraciadamente, los afloramientos mineros y las colecciones de minerales y fósiles encontrados en dichos afloramientos no son normalmente reconocidos, sin embargo, representan un patrimonio geológico muy valioso. Los sitios mineros en Croacia no están adecuadamente protegidos a excepción de dos canteras de piedra. En este artículo, se presentan varias minas y canteras reconocidas por agentes locales como sitio turístico que debería ser tenido en consideración por las autoridades responsables del patrimonio geológico. La preservación del patrimonio geológico en el marco del patrimonio minero es fundamental para promover la protección, valorización y utilización de antiguos yacimientos mineros como destinos geo-turísticos

Croatian geological heritage related to historical mining

Geološka baština (ili „geobaština“) obuhvaća prirodne geološke ili geomorfološke značajke koje posjeduju estetsku, intrinzičnu, znanstvenu i obrazovnu vrijednost te pružaju jedinstven uvid u geološke procese koji utječu na formiranje ili evoluciju Zemlje. Često samo ljudskim djelovanjem te značajke dolaze na vidjelo. U tom slučaju možemo istodobno govoriti o prirodnoj (geološkoj), kao i o kulturnoj (povijesnoj, industrijskoj, rudarskoj) baštini, odnosno nasljeđu. Geo-baština se može podijeliti na „in situ“ (npr. izdanak određene stijene) i „ex situ“ (npr. zbirke minerala). U Hrvatskoj su isključivo zbog vrijedne geobaštine zaštićena 53 lokaliteta i to u kategorijama posebnog rezervata (paleontološkog i geografsko-botaničkog) i spomenika prirode (geološkog, paleontološkog, geološko-paleontološkog, geomorfološkog, geološko-geografskog i hidrološkog). Osim toga postoji i jedan slučaj u kategoriji zaštićenog minerala. Geobaština se nalazi i unutar većih zaštićenih područja kao što su strogi rezervati (npr. Hajdučki i Rožanski kukovi), nacionalni parkovi (npr. Paklenica), parkovi prirode (npr. Papuk koji je ujedno i geopark), regionalni parkovi (npr. Moslavačka gora) i značajni krajobrazi (npr. Baraćeve špilje). Eksploatacija geoloških resursa odigrala je važnu ulogu u razvoju čovječanstva od prapovijesti do danas. Stoga povijesne rudarske lokacije predstavljaju vrijednu industrijsku, kulturnu i znanstvenu baštinu za Hrvatsku koja ima dugu rudarsku tradiciju. Osim toga, mnogi površinski i podzemni izdanci stvoreni rudarenjem, kao i „ex situ“ zbirke minerala, stijena ili fosila pronađenih na tim mjestima, predstavljaju vrijednu geološku baštinu. U Hrvatskoj je kamen najvažniji resurs koji se iskorištava kroz povijest, s mnogo napuštenih kamenoloma koji bi potencijalno mogli predstavljati geološku baštinu. Među njima su samo dva zaštićena kao geološki spomenici prirode. Rupnica kod Voćina prvi je geološki spomenik u Hrvatskoj, a zaštićen je zbog stupastog lučenja albitnog riolita. Kamenolom Fantazija kod Rovinja jedinstven je primjer sedimentologije karbonatnih stijena. Iako u Hrvatskoj danas nema potencijalnih rudnih ležišta, u prošlosti je proizvodnja metala bila značajna. Iako nisu zaštićena kao geološka baština, dva su mjesta revitalizirana za potrebe geoturizma (rudnik bakra Rude i rudnik srebra Zrinski). Postoji i nekoliko važnih povijesnih nalazišta nemetalnih minerala. Nažalost, do sada nijedno nije dostupno široj zajednici. Međutim, Muzej Radboa je dobar primjer kako se takva nalazišta i rudarska tehnologija (rudnik sumpora i radobojski stroj) mogu predstaviti javnosti. Ugljen i bitumen su također rudareni u Hrvatskoj. Rudarska tradicija vezana uz ugljenokope očuvana je u obliku nematerijalne baštine (npr. Rudarska četa u Ivancu). Na temelju gore navedenog, postoji dovoljno prostora za rad na promociji geološke baštine vezane uz rudarstvo u Hrvatskoj. Očuvanje geološke baštine u kontekstu rudarskog naslijeđa od temeljne je važnosti za promicanje odgovarajuće zaštite, valorizacije i mogućeg budućeg korištenja kao geoturističkih lokaliteta. Stoga je tekući europski projekt cjeloživotnog učenja „MineHeritage: Historical Mining – Tracing and Learning from Ancient Materials and Mining Technology“ dobra osnova za dugoročno planiranje geokonzervacije. Cilj ovog projekta je podizanje svijesti društva o upotrebi i potrebi za sirovinama. Budući da je projekt u svojoj početnoj fazi, osim očekivanih rezultata, bit će predstavljeni unosi za europsku bazu podataka o starim rudarskim mjestima, napuštenim rudnicima, i klasificiranoj baštini vezanoj uz povijesno rudarstvo Hrvatske.The geological heritage (or ‘geo-heritage’) encompasses natural geological or geomorphological features possessing aesthetic, intrinsic, scientific and educational value, that provide unique insight into geological processes affecting the formation or evolution of the Earth. Often, only by human activity, these features come to light. In that case, we can talk at the same time of natural (geological), as well as cultural (historical, industrial, mine) heritage. Geo-heritage can be divided to “in situ” (e.g. outcrop of a specific rock) and “ex situ” (e.g. mineral collection). In Croatia, 53 localities are protected exclusively due to their geological value. Those localities have different level of protection, special reserves (paleontological and geographic-botanical)and nature monuments (geological, paleontological, geological-paleontological, geomorphological, geological-geographic and hydrological). In addition, there is one case of protected minerals. Geo-heritage in Croatia is located within the larger protected areas such as strict reserves (e.g. Hajdučki i Rožanski kukovi), national parks (e.g. Paklenica), nature parks (e.g. Papuk which is also Geopark), regional parks (e.g. Moslavačka gora) and significant landscapes (e.g. Barać caves etc.). Exploitation of geological resources has played an important role in the development of mankind since prehistory until the present days. Hence, historical mining sites represent valuable industrial, cultural and scientific heritage for Croatia which has a long mining tradition. In addition, many surface and underground outcrops that were opened by quarrying and mining, as well as ex situ collections of minerals, rocks or fossils found at such sites, represent valuable geological heritage. In Croatia, stone material has been the most important resource exploited throughout history, with many abandoned quarries that could potentially represent geological heritage sites. Among them, only two are already protected as geological monuments of nature, Rupnica near Voćin where columnar albite rhyolite became the first protected geological site in Croatia and quarry Fantazija near Rovinj as unique example of carbonate sedimentology. Although, in Croatia nowadays there is no potential ore deposits, there were times in the past when metal production was significant. Although not protected as geological heritage, two sites are revitalised for geotourism (copper mine Rude and silver mine Zrinski). There are also several important historical mining sites of non-metallic minerals. Unfortunately, so far, none of them are accessible to wider society. However, Radboa museum is good example how such sites and mining technology (sulphur mine and Radoboj machine) could be presented to public. Coal and bitumen were mined in Croatia as well. Mining tradition at some coal mining places is preserved in the form of non-material heritage (e.g. Rudarska četa in Ivanec). Based on the above, there is plenty of room for work on the promotion of geological heritage related to mining in Croatia. Preservation of geological heritage within the mining heritage context is fundamental to promote proper protection, valorisation and possible future utilization as geotouristic sites. Hence, running European wider society learning project “MineHeritage: Historical Mining – Tracing and Learning from Ancient Materials and Mining Technology” is a good basis for longer-term planning of geoconservation. The aim of this project is to raise society’s awareness of usage and need for raw materials. Since the project is in its initial phase, beside expected outcomes, entries for the European database on ancient mining sites, abandoned mines, classified heritage sites related to historical mining in Croatia will be presented

Croatian geological heritage related to historical mining

Geološka baština (ili „geobaština“) obuhvaća prirodne geološke ili geomorfološke značajke koje posjeduju estetsku, intrinzičnu, znanstvenu i obrazovnu vrijednost te pružaju jedinstven uvid u geološke procese koji utječu na formiranje ili evoluciju Zemlje. Često samo ljudskim djelovanjem te značajke dolaze na vidjelo. U tom slučaju možemo istodobno govoriti o prirodnoj (geološkoj), kao i o kulturnoj (povijesnoj, industrijskoj, rudarskoj) baštini, odnosno nasljeđu. Geo-baština se može podijeliti na „in situ“ (npr. izdanak određene stijene) i „ex situ“ (npr. zbirke minerala). U Hrvatskoj su isključivo zbog vrijedne geobaštine zaštićena 53 lokaliteta i to u kategorijama posebnog rezervata (paleontološkog i geografsko-botaničkog) i spomenika prirode (geološkog, paleontološkog, geološko-paleontološkog, geomorfološkog, geološko-geografskog i hidrološkog). Osim toga postoji i jedan slučaj u kategoriji zaštićenog minerala. Geobaština se nalazi i unutar većih zaštićenih područja kao što su strogi rezervati (npr. Hajdučki i Rožanski kukovi), nacionalni parkovi (npr. Paklenica), parkovi prirode (npr. Papuk koji je ujedno i geopark), regionalni parkovi (npr. Moslavačka gora) i značajni krajobrazi (npr. Baraćeve špilje). Eksploatacija geoloških resursa odigrala je važnu ulogu u razvoju čovječanstva od prapovijesti do danas. Stoga povijesne rudarske lokacije predstavljaju vrijednu industrijsku, kulturnu i znanstvenu baštinu za Hrvatsku koja ima dugu rudarsku tradiciju. Osim toga, mnogi površinski i podzemni izdanci stvoreni rudarenjem, kao i „ex situ“ zbirke minerala, stijena ili fosila pronađenih na tim mjestima, predstavljaju vrijednu geološku baštinu. U Hrvatskoj je kamen najvažniji resurs koji se iskorištava kroz povijest, s mnogo napuštenih kamenoloma koji bi potencijalno mogli predstavljati geološku baštinu. Među njima su samo dva zaštićena kao geološki spomenici prirode. Rupnica kod Voćina prvi je geološki spomenik u Hrvatskoj, a zaštićen je zbog stupastog lučenja albitnog riolita. Kamenolom Fantazija kod Rovinja jedinstven je primjer sedimentologije karbonatnih stijena. Iako u Hrvatskoj danas nema potencijalnih rudnih ležišta, u prošlosti je proizvodnja metala bila značajna. Iako nisu zaštićena kao geološka baština, dva su mjesta revitalizirana za potrebe geoturizma (rudnik bakra Rude i rudnik srebra Zrinski). Postoji i nekoliko važnih povijesnih nalazišta nemetalnih minerala. Nažalost, do sada nijedno nije dostupno široj zajednici. Međutim, Muzej Radboa je dobar primjer kako se takva nalazišta i rudarska tehnologija (rudnik sumpora i radobojski stroj) mogu predstaviti javnosti. Ugljen i bitumen su također rudareni u Hrvatskoj. Rudarska tradicija vezana uz ugljenokope očuvana je u obliku nematerijalne baštine (npr. Rudarska četa u Ivancu). Na temelju gore navedenog, postoji dovoljno prostora za rad na promociji geološke baštine vezane uz rudarstvo u Hrvatskoj. Očuvanje geološke baštine u kontekstu rudarskog naslijeđa od temeljne je važnosti za promicanje odgovarajuće zaštite, valorizacije i mogućeg budućeg korištenja kao geoturističkih lokaliteta. Stoga je tekući europski projekt cjeloživotnog učenja „MineHeritage: Historical Mining – Tracing and Learning from Ancient Materials and Mining Technology“ dobra osnova za dugoročno planiranje geokonzervacije. Cilj ovog projekta je podizanje svijesti društva o upotrebi i potrebi za sirovinama. Budući da je projekt u svojoj početnoj fazi, osim očekivanih rezultata, bit će predstavljeni unosi za europsku bazu podataka o starim rudarskim mjestima, napuštenim rudnicima, i klasificiranoj baštini vezanoj uz povijesno rudarstvo Hrvatske.The geological heritage (or ‘geo-heritage’) encompasses natural geological or geomorphological features possessing aesthetic, intrinsic, scientific and educational value, that provide unique insight into geological processes affecting the formation or evolution of the Earth. Often, only by human activity, these features come to light. In that case, we can talk at the same time of natural (geological), as well as cultural (historical, industrial, mine) heritage. Geo-heritage can be divided to “in situ” (e.g. outcrop of a specific rock) and “ex situ” (e.g. mineral collection). In Croatia, 53 localities are protected exclusively due to their geological value. Those localities have different level of protection, special reserves (paleontological and geographic-botanical)and nature monuments (geological, paleontological, geological-paleontological, geomorphological, geological-geographic and hydrological). In addition, there is one case of protected minerals. Geo-heritage in Croatia is located within the larger protected areas such as strict reserves (e.g. Hajdučki i Rožanski kukovi), national parks (e.g. Paklenica), nature parks (e.g. Papuk which is also Geopark), regional parks (e.g. Moslavačka gora) and significant landscapes (e.g. Barać caves etc.). Exploitation of geological resources has played an important role in the development of mankind since prehistory until the present days. Hence, historical mining sites represent valuable industrial, cultural and scientific heritage for Croatia which has a long mining tradition. In addition, many surface and underground outcrops that were opened by quarrying and mining, as well as ex situ collections of minerals, rocks or fossils found at such sites, represent valuable geological heritage. In Croatia, stone material has been the most important resource exploited throughout history, with many abandoned quarries that could potentially represent geological heritage sites. Among them, only two are already protected as geological monuments of nature, Rupnica near Voćin where columnar albite rhyolite became the first protected geological site in Croatia and quarry Fantazija near Rovinj as unique example of carbonate sedimentology. Although, in Croatia nowadays there is no potential ore deposits, there were times in the past when metal production was significant. Although not protected as geological heritage, two sites are revitalised for geotourism (copper mine Rude and silver mine Zrinski). There are also several important historical mining sites of non-metallic minerals. Unfortunately, so far, none of them are accessible to wider society. However, Radboa museum is good example how such sites and mining technology (sulphur mine and Radoboj machine) could be presented to public. Coal and bitumen were mined in Croatia as well. Mining tradition at some coal mining places is preserved in the form of non-material heritage (e.g. Rudarska četa in Ivanec). Based on the above, there is plenty of room for work on the promotion of geological heritage related to mining in Croatia. Preservation of geological heritage within the mining heritage context is fundamental to promote proper protection, valorisation and possible future utilization as geotouristic sites. Hence, running European wider society learning project “MineHeritage: Historical Mining – Tracing and Learning from Ancient Materials and Mining Technology” is a good basis for longer-term planning of geoconservation. The aim of this project is to raise society’s awareness of usage and need for raw materials. Since the project is in its initial phase, beside expected outcomes, entries for the European database on ancient mining sites, abandoned mines, classified heritage sites related to historical mining in Croatia will be presented

Historical mining in Croatia - valuable examples for European MineHeritage project

MineHeritage – “Tracing and learning from ancient materials and mining technology” is a running Wider Society Learning project with the main goal to raise society’s awareness of usage and need for raw materials. Duration of the project is three years (1.1.2019 – 31.12.2021) with total budget of 974, 245.00 € founded by European Institute of Innovation & Technology (EIT) in the frame of Knowledge and Innovation Community (KIC) Raw Materials. Project consortium consists of 13 partners from eleven European countries, with Faculty of Mining, Geology and Petroleum Engineering as one of them. Leading partner is New University of Lisbon - Faculty of Sciences and Technology (FCT NOVA) from Portugal. The scope of the MineHeritage project is wider understanding of the mining technologies and raw materials uses and trades in different regions of Europe during specific historical periods (since prehistory) with the resulting impact on development of European society. The objectives of the projects are following: (1) to engage dissemination approaches to cross-generational target audiences on mining and raw materials as a unifying common ground for Europe through an historical perspective ; (2) to promote synergies with other actors such as schools, museums, local administration and mining companies ; (3) to involve society in raw materials and mining through knowledge, (4) to build multicultural bridges between different regions in Europe ; (5) to stimulate the debate on environmental sustainability in mining and raw materials sector ; (6) to develop popular science materials and organise popular science events ; and (7) to raise awareness of own cultural heritage and history of a region. End users of the project are school age children (13-19 years) and young adults (20-45 years). Expected project outcomes are: (1) database with information on ancient mining sites, abandoned mines, classified heritage sites related to mining from different EU countries participating in the project ; (2) popular science materials (booklets and videos on specific mining sites) ; (3) interactive multilevel game with historical and regional perspective of mining and raw materials in Europe ; (4) mobile application for cultural tourism involving historical mining sites ; (5) social media accounts (Facebook, Instagram, LinkedIn and YouTube) dedicated to the dissemination of historical mining sites, events and news ; (6) promotion of popular science materials (talks, lectures, discussion events, excursions) ; (7) collaboration with local administration, tourist offices, schools, museums, as well as with other KIC running programs. The emphasis of the presentation will be on up-to-date information related to Croatian historical mining sites collected for the database, promotional activities of the Croatian team as well as established collaborations. Croatia has a long mining tradition and heritage. Exploitation of natural and crushed stone together with sand and gravel for civil engineering purposes has represented the most important raw material exploited in Croatia throughout our history to the present days. Although, there is no potential in Croatian ore deposits nowadays, there were times in the past when metal production (Ag, Zn, Pb, Cu, Fe) was significant (e.g. Trgovska gora ; Rude). There are also several distinct historical mining sites of non-metallic minerals (e.g. sulphur in Radoboj ; bauxite in the Mirna valley in Istria). Notwithstanding out of interest for KIC Raw Material, we will present several coal mines, especially when they were related to mining of other commodities (e.g. coal and zinc in Ivanec). Historical examples of technologies related to mining in Croatia will also perfectly contribute to the overall project (e.g. Radoboj machine for sulphur refinement shown on Figure 1 ; blast furnace from Bešlinec). Alongside traditional promotional materials as brochures and videos, important localities will be promoted using geocaches (traditional and EarthCaches)

A COMPARISON OF DIFF ERENT RINSING METHODS UPON SELECTIVE DISSOLUTION OF IRON (OXY)HYDROXIDES IN SOILS/SEDIMENTS

Željezovi (oksi)hidroksidi imaju važnu ulogu u različitim disciplinama, među ostalim u zaštiti okoliša, prospekciji rudnih ležišta, mineralogiji, geologiji i pedologiji. U postupcima selektivnoga otapanja, bilo da su namijenjeni uklanjanju (oksi)hidroksida prije analize minerala gline ili za određivanje metala u reducirajućoj frakciji tla/sedimenta, vrlo je važno sačuvati cijeli neotopljeni ostatak. Stoga su ciljevi ovoga rada bili: (1) odrediti najučinkovitiju metodu ispiranja reagensa nakon otapanja (oksi)hidroksida i (2) provjeriti može li se sadržaj željezova (oksi)hidroksida odrediti gravimetrijski. Testirane su sljedeće metode ispiranja: (1) centrifugiranje, (2) filtriranje, (3) dijaliza. Analiza je provedena na uzorku crvenice koji sadržava 5,12 % Fe2O3. Vrijeme potrebno za ispiranje povećava se ovim redoslijedom: centrifugiranje < filtriranje < dijaliza. Udio gravimetrijski određene otopljene frakcije znatno se razlikuje ovisno o odabranoj metodi ispiranja te je neusporedivo veći od udjela Fe2O3 određenoga mjerenjem željeza u ekstraktu nakon otapanja. Najučinkovitija metoda ispiranja ditionit-citrat-bikarbonata nakon otapanja (oksi)hidroksida jest dijaliza. Prednost je ove metode u tome što nema gubitka uzorka, a nedostatak je vrijeme potrebno za njezino provođenje. Centrifugiranje je relativno brza metoda, no može dovesti do gubitka sitnih čestica. U ovome istraživanju gubitak je bio neprihvatljivo velik. Filtriranje pomoću fi ltarskoga papira oduzima više vremena od centrifugiranja te je pokazalo najlošije rezultate. Na temelju rezultata možemo zaključiti: (1) sadržaj željezova (oksi)hidroksida ne može se odrediti gravimetrijski nakon selektivnoga otapanja; (2) način ispiranja reagensa nakon uklanjanja željezova (oksi)hidroksida pri pripremi uzoraka za analizu minerala glina treba biti pažljivo odabran i izveden; (3) centrifugiranje, uobičajena metoda ispiranja u svim postupcima sekvencijske ekstrakcijske analize, može dovesti do krivih rezultata.Iron (oxy)hydroxides play an important role in a variety of disciplines, among others, environmental and exploration geochemistry, mineralogy, geology and soil science. In selective leaching procedures, either for the removal of (oxy)hydroxide prior to clay minerals analysis or for the determination of metals in reducible soil/sediment fractions, it is very important to preserve the entire undissolved residue. Therefore, the objectives of the study were: (1) to fi nd the most effective reagent rinsing method which follow the dissolution of (oxy)hydroxides; and (2) to test if the content of Fe (oxi)hydroxides could be determined gravimetrically. The following reagent rinsing methods were tested: (1) centrifugation, (2) filtration, (3) dialysis. The analysis was conducted on the sample of red soil with 5.12% Fe2O3. The time needed for rinsing increased in this order: centrifugation < fi ltration < dialysis. The amount of gravimetrically determined dissolved reducible fraction upon rinsing varies signifi cantly depending on the methods and it is remarkably higher than the amount of Fe2O3 calculated from iron content determined by atomic absorption in leachate. The most effective reagent rinsing method which follows the dissolution of (oxy)hydroxides using dithionite-citrate-bicarbonate is dialysis. No loss of sample is the advantage of this method, but its disadvantage is time needed for its completion. Centrifugation is relatively rapid, but can lead to loss of the smaller particles. In this case the loss was unacceptably great. Filtration using filter paper is more time consuming than centrifugation and it showed the worst results. The conclusions are that: (1) the content of Fe (oxi)hydroxides cannot be determined gravimetrically upon selective leaching; (2) rinsing of reagents after Fe (oxi)hydroxide removal prior to clay mineral analysis should be carefully selected and performed; (3) centrifugation, accepted rinsing method in all sequential extraction sequences, can cause misleading results

Hrvatski kamen u Zagrebu : [brošura]

This booklet was created in the framework of the Project MineHeritage: Historical Mining - Tracing and Learning from Ancient Materials and Mining Technology. Booklet: no. 4, v. 13.Letak [i. e. brošura] je pripremljen u sklopu projekta MineHeritage: Historical Mining - Tracing and Learning from Ancient Materials and Mining Technology. Letak [i. e. brošura]: no. 4, v. 13

Geological and mining heritage : Croatian historical mining sites : [poster]

Plakat

Radoboj : [brošura]

This booklet was created in the framework of the Project MineHeritage: Historical Mining - Tracing and Learning from Ancient Materials and Mining Technology. Booklet: no. 2, v. 13.Letak [i. e. brošura] je pripremljen u sklopu projekta MineHeritage: Historical Mining - Tracing and Learning from Ancient Materials and Mining Technology. Letak [i. e. brošura]: no. 2, v. 13

Natural stone : famous natural stone varieties in Croatia : [poster]

Plakat