A brief description of the color types for ruby and sapphire used at Lotus Gemology.
An introduction to the ruby & sapphire color types used at Lotus Gemology.
From Peacock to Pigeon's Blood Order Page
A 2006 mission to remote ruby and spinel localities in Tajikistan.
A loving look at ruby – the gem of passion – from the standpoint of the connoisseur.
An examination of the problem of separating pink sapphire and padparadscha from ruby.
World auction records for ruby, sapphire and spinel.
Ruby, Sapphire & Spinel: An Archaeological, Textual and Cultural Study By Derek J. Content, 2016. Brepols Publishers, Turnhout, Belgium, www.brepols.net, 452 pages, illus., ISBN 978-2503568089. €150.00 hardcover.
A discussion of rutile silk in corundum and its use in detecting artificial heat treatment. Careful examination of these "silk" inclusions can provide vital clues to unmask heated gems.
In 1878, the noted Austrian mineralogist, Gustav Tschermak von Seysenegg [1836–1927], was the first to properly identify silk in corundum, finding it to be composed of the mineral rutile (TiO2). An English translation of his landmark paper is included, along with the original German version.
Since the turn of the millennium, the price of fine spinel has risen at an incredible pace. No longer simply the poor man's ruby, spinel is finally getting the attention it deserves as one of the world's premier gems.
No one can go it alone. We would like to thank the many individuals who have helped us over the years. Please excuse us if we have missed anyone.
Virtually all gemologists are aware of the curved growth lines and gas bubbles in Verneuil (flame-fusion) synthetic corundum, but few understand exactly why they occur and how they are distributed in these stones. This article clarifies these important identifying features.
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