'Universidad de Sevilla - Secretariado de Recursos Audiovisuales y Nuevas Tecnologias'
Abstract
Gemstones are defined as rare minerals having a high clarity, a high hardness and
showing a bright colour and a nice shining. The most important gems are diamond,
sapphire and emerald. These gems are callad precious stones.
Gems have fascinated man since the earliest times. They have always been sought
out by man for their aesthetic and symbolic valué. Due to their scarceness and high
'^alue, gems were appreciated by the mighty ones as a sign of their power (emperors
^nd kings, dignitaries of religions ...). Their high hardness and henee strong resismnce
to deterioration symbolised the everlastingness of their reign. This last property is interesting
from an archaeological point of view: gemstones travel through time without
noticeable alteration, even buried in aggressive environment. On the other hand, gems
oiay be used several times on different jewels, possibly cut and polished again. Like
spices and other precious and sought-after items, gems were brought back from long
distance. Accordingly, they are good tracers for ancient trading routes and influence
of civilisations. Each civilisation had its own favourite gemstones: lapis lazuli in Egypt;
amber and emerald in the Román Empire; gamet in early Middle Ages westem civil
isations; jade, ruby and sapphire in Far-East cultures. Moreover, the provenance of
some ancient gems such as emeralds or gamets is still debated. For all these reasons,
the study of gems kept in museum collections is a promising research fíeld
