Gemmology
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Saturday, 24 July 2021


Gemmology — gemstones — characteristics, classification, specimens, library
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GEMMOLOGY — GEMSTONES

characteristics, classification, specimens, library

As gemstones we accept cut specimens of crystals of natural mineral species having a visible transparency and certain durability. From over 4800 known minerals (according to data of the International Mineralogical Association), approximately 150 satisfy the above conditions and form crystals of sufficient size to be cut.

The section ‘Classification’ presents descriptions of 171 different kinds of natural gemstones (106 mineral species). The Nickel-Strunz systematic order (10th edition) is used. Since gemmology does not always follow the systematics of minerals in naming, many popular varieties or just ’names’ are listed.

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Classification
Featured

Danburite

— In granite and metamorphosed carbonate rocks associated with hydrothermal activity (Anthony et al., 2001—2005).
Danburite

The section ‘Repository’ contains data and photos of 760 specimens of gemstones. The smallest is just 1.96 mm (0.02 ct) ruby from Mozambique, and the largest — 70.11 mm (326.60 ct) rock crystal from Africa. Besides there are 8 specimens of synthetic stones.

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Repository
Rose quartz — specimen 0175

Some exceptional specimens of gemstones from our ‘Repository’

More specimens of gemstones
Pleonaste — specimen 0385
Cordierite — specimen 0389
Cordierite — specimen 0390
Agate — specimen 0392

— More from ‘Repository

Currently there are 283 bibliographical references and abstracts to publications with gemmological or mineralogical thematics in the ‘Library’. The section comprises also a glossary with 391 terms.
Library
Glossary

prehnite — species of mineral; see prehnite in ‘Classification’
prismatine — species of mineral; faceted specimens exist
psilomelane — obsolete name; see psilomelane in ‘Classification’
pyrite — species of mineral; faceted specimens exist
Publications

Anthony, J. W., Bideaux, R. A., Bladh, K. W., Nichols, M. C. (Eds), 2001—2005 — Sillimanite — Features the data of sillimanite; from ‘Handbook of Mineralogy’.
Anthony, J. W., Bideaux, R. A., Bladh, K. W., Nichols, M. C. (Eds), 2001—2005 — Andalusite — Features the data of andalusite; from ‘Handbook of Mineralogy’.