English | Български
Wednesday, 19 January 2022

Gemmology — gemstones — characteristics, classification, specimens, library


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.

Quick navigation selector



— Most common in felsic volcanic rocks; in volcanic glass; also from mafic, high-temperature contact metamorphic, and hydrothermally altered rocks; from eclogite nodules in kimberlite (Anthony et al., 2001—2005).

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.

Gallery view selector

Colour selector
Simple colour schemeredorangey redreddish orangeorangeorangey yellowyellowgreenish yellowyellowish greenslightly yellowish greengreenvery slightly bluish greenbluish greenvery strongly bluish greengreen-blue or blue-greenvery strongly greenish bluevery slightly greenish bluebluevioletish bluebluish violetvioletbluish purplepurplereddish purplestrongly purplish redslightly purplish redcolourlessgreyblack
Rock crystal — specimen 0191

Some exceptional specimens of gemstones from our ‘Repository’

More specimens of gemstones
Bowenite — specimen 0152
Moonstone — specimen 0162
Moonstone — specimen 0163
Magnesite — specimen 0164

— 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.

eclogite — a mafic (basaltic in composition) metamorphic rock
ekanite — species of mineral
elbaite — species of mineral; see elbaite in ‘Classification’
emerald — variety of beryl; see emerald in ‘Classification’

Freiesleben, J. C., 1836 — Calcit — Published in 1836 in ‘Magazin für die Oryktographie von Sachsen’; contains the original description of the mineral calcite.
Karsten, D. L. G., 1808 — Erd-und steinarten. Magnesit — Published in 1808 in ‘Mineralogische Tabellen’; contains the original description of the mineral magnesite.