Ruby and Sapphire Production and Distribution: A Quarter Century of Change

Petrogenesis of alkaline basalt-hosted sapphire megacrysts. Petrological and geochemical investigations of in situ sapphire occurrences from the Siebengebirge Volcanic Field, Germany

“…Of special interest are secondary corundum deposits that are associated with rift-related alkaline basaltic volcanism as these are among the world's largest gem corundum suppliers (e.g., Guo et al 1996;Limtrakun et al 2001;Shore and Weldon 2009) and are hence economically of great importance. Such basaltic secondary deposits are located all over the world, most notably in Asia (e.g., Guo et al 1996, and in eastern Australia, at the western Pacific margin (e.g., Coenraads 1990;Graham et al 2008;Sutherland 1996;Sutherland et al 1998aSutherland et al , 2002Sutherland et al , 2009bSutherland et al , 2015Sutherland et al , 2017Saminpanya 2001;McGee 2005;Abduriyim et al 2012), but also in Europe (e.g., Malikova 1999;Giuliani et al 2009;Uher et al 2012), Africa (Kiefert and Schmetzer 1987;Krzemnicki et al 1996;Schwarz et al 2000;Pardieux et al 2014), in South America , and in North America (e.g., Garland 2002;Berg 2007Berg , 2014Palke et al 2017).…”

An Era of Sweeping Change in Diamond and Colored Stone Production and Markets

“…Most of the production was in tourmalines, sapphires (e.g., figure 7), and rubies, but a new gem mineral-pezzottaite-was also introduced. At its peak in 2007, the sector employed close to 100,000 people (Shor and Weldon, 2009).…”

“…The previous ban, enacted in 2003, did not cover Burmese gems that were cut in a third country. The cumulative sanctions caused Burmese ruby production to drop by an estimated 50% (Shor and Weldon, 2009 Because Myanmar produced an estimated 90% of fine-and commercial-quality ruby, while Madagascar embargoed exports as noted above, supplies of ruby and sapphire slowed greatly. This not only created worldwide shortages of gem corundum, but it also proved devastating to Thailand's gemstone cutting industry (Shor and Weldon, 2009).…”

Gemstone Enhancement and Its Detection in the 2000s

“…The decade yielded rich contributions in this area; see Shor and Weldon (2009) and Shigley et al (2010) for important literature references. Smith et al (2008d) and Smith (2010) provided useful charts for identifying the natural or treated state in rubies and sapphires from around the world.…”

“…The 2000s ushered in a greater understanding of this material-which dominated the ruby market-and cooperation between gemological laboratories to adopt standardized wording to describe heat treatment in corundum and, most importantly, the degree to which fracture "healing" has occurred and the amount of solidified flux "residue" (see e.g., www.lmhc-gemology.org/index.html). Today, there is less production of ruby at Mong Hsu, but this technique is now being used on rubies from Africa (Shor and Weldon, 2009). …”