Gemmology
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Sunday, 22 April 2018


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 172 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

Titanite

— Also known as sphene; a common accessory mineral in intermediate and felsic rocks, pegmatites, and alpine veins; in gneisses, schists, and some skarns (Anthony et al., 2001—2005).
Titanite

The section ‘Repository’ contains data and photos of 745 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
Topaz — specimen 0286

Some exceptional specimens of gemstones from our ‘Repository’

More specimens of gemstones
Opal — specimen 0167
Johachidolite — specimen 0174
Jadeite — specimen 0200
Smoky quartz — specimen 0202

— 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 392 terms.
Library
Glossary

indochinite — тип тектит; виж индошинит в ‘Класификация’
intrusion — a liquid rock that forms under Earth’s surface
iolite — name of gemstone of the mineral cordierite
jadeite — species of mineral; see jadeite in ‘Classification’
Publications

Anthony, J. W., Bideaux, R. A., Bladh, K. W., Nichols, M. C. (Eds), 2001—2005 — Dolomite — Features the data of dolomite; from ‘Handbook of Mineralogy’.
Anthony, J. W., Bideaux, R. A., Bladh, K. W., Nichols, M. C. (Eds), 2001—2005 — Aragonite — Features the data of aragonite; from ‘Handbook of Mineralogy’.