Gems and Minerals from the Sub-Arctic
Circumnavigate the boreal reaches of the globe to explore gems from polar regions.
Star Spinel with Four and Six Rays
A cabochon displaying asterism is found to be an untreated spinel with two different stars.
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.
Abstracts; Summer 1991
From the Summer 1991 issue of Gems & Gemmology, a summary of important gemmology-related articles published in other journals.
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 colour - and synthetic material, have led to difficulties in the recognition of the natural stones by traditional methods.
Abstracts; Winter 1991
This article, from the Winter 1991 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
Abstracts; Autumn 1991
This article, from the Autumn 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemology.
Gemstones of Pakistan: Emerald, Ruby and Spinel
This article reports on three gem materials currently being mined in Pakistan.