Gems and Minerals from the Subarctic
Circumnavigate the boreal reaches of the globe to explore gems from polar regions.
Etch Marks, Negative Crystals, and Etch Tubes in Spinel from Madagascar
A spinel from Madagascar, mixed in with a parcel of blue sapphire, exhibited an array of internal features.
Violetish Blue Spinel in Yellow Sapphire
A singly refractive inclusion within a yellow sapphire proves to be spinel.
Large Faceted Hibonite
A hibonite of unusual size examined in the Carlsbad lab is host to a spinel inclusion.
Spinel Inclusion in Spinel
Examination of a pink-purple spinel revealed what appeared to be a spinel crystal inclusion.
'Cobalt-Blue' Gem Spinels
Similarities between natural spinels — with intense blue color — and synthetic material, have led to difficulties in the recognition of the natural stones by traditional methods.
Gemstones of Pakistan: Emerald, Ruby, and Spinel
This article reports on three gem materials currently being mined in Pakistan.
Sri Lanka: The Gem Island
An overview of the many types of gem-quality material, and its inclusions, currently found in Sri Lanka.
Abstracts; Winter 1991
This article, from the Winter 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.
Abstracts; Fall 1991
This article, from the Fall 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.