Coloration of amethyst and smoky quartz

15 p. : ill. ; 24 cm.Includes bibliographical references (p. 14-15)

Incrustations upon crystal forms

4 p. : ill. ; 24 cm.Sphalerite incrusting galena -- Selectively coated quartz crystals -- Chalcopyrite incrusting sphalerite

Twisted crystals of pyrite and quartz

6 p. : ill. ; 24 cm.Includes bibliographical references (p. 5-6).Pyrite, French Creek, Chester County, Pennsylvania -- Smoky quartz, El Paso County, Colorado

United States Geological Survey Reports

Report discussing the mineral composition and other properties of gummite or "fine-grained yellow to orange-red alteration products of uraninite whose true identity is unknown." Sections include the history and nomenclature of gummite, chemical analyses of gummite, sequential alteration of gummite, and description of minerals in gummite

Mineral incrustations upon crystals

11 p. : ill. ; 24 cm.Includes bibliographical references.Dolomite incrusting rhodochrosite -- Fluorite incrusting calcite -- Marcasite incrusting calcite -- Pyrite incrusting calcite -- Tetrahedrite and chalcopyrite incrusting sphalerite -- Tetrahedrite incrusting chalcopyrite -- Hematite incrusting calcite -- Miscellaneous occurrences."Instances are described of mineral incrustations confined to the edges or corners of the incrusted crystals. The effect is explained by the greater adsorptive power of these portions of the crystal surface. Adsorption by the edges and corners of growing crystals may be accompanied by a change in crystal habit, modifying faces being developed which suppress the adsorbing edge or corner"--P. [1]

United States Geological Survey Reports

From introduction: "Pending publication of this volume and in response to a widespread demand among workers in uranium and thorium mineralogy, the X-ray powder diffraction data for the known minerals that contain uranium or thorium as an essential constituent are presented here. The coverage is complete except for a few minerals for which there are no reliable data owing to lack of authentic specimens.