KYANITE: TUCSON 2018 JOGS

After hitting the Westward Look Resort Show I headed over to the JOGS Tucson Gem and Mineral Show.  JOGS is one of the “giant” shows with several hundred dealers (I was too lazy to count) and is restricted to wholesale buyers and “buyer tags” are required for entrance.  I was able to attend with a qualified buyer and purchase a “public guest” ticket.  JOGS is hard to describe—gigantic, more jewelry than I have ever seen in one place, beautiful multi-thousand dollars rings and pendants, faceted gem stones of all kinds from locations around the world, less expensive sterling silver jewelry with nice semi-precious stones, lots of findings (parts for jewelry making), and a few minerals (mostly amethyst cathedrals).  I also noted that many/most dealers had a minimum purchase, usually $200-300.  This certainly was a venue for purchasing jewelry in large lots at wholesale prices for later retail sales.  I listened as one buyer purchased 300 black onyx rings of mixed sizes, mostly 6,7,8.  Each ring was packed in an individual “cellophane” bag with a size label. But I must admit that after looking at a couple of hundred booths most items appeared similar!

Large clusters of elongated kyanite crystals priced at ~$100---$150. The largest single crystal is ~20 cm.

The most impressive mineral display, IMHO, were the large kyanite specimens from Minas Gerais, Brazil (the best information I could get from the Dealer). Kyanite is an aluminum silicate [Al₂₍SiO₄)O] that comes in a variety of colors (white, black, blue-gray, gray, orange, green, black, and more) with vivid blue being the common variety and the favorite of collectors.  Crystals, often bladed and long, are transparent to translucent with a vitreous to pearly luster.  It is a very distinctive mineral and seems easy to identify.  In addition to form, kyanite has a variable hardness--- around 5 (Mohs) parallel to the C-Axis (long part of the crystal) and around 7 (Mohs) perpendicular to the C-Axis.

My hand specimen of kyanite ~14 cm. purchased for $5.  The light colored matrix appears to be talc and a small amount of quartz.

Kyanite is a metamorphic mineral and its presence indicates a specific temperature and pressure range.  It is one of three aluminum silicate trimorphs with the other two being sillimanite and andalusite.  I have other colors of kyanite in my collection (not with me) and several specimens of the other trimorphs; therefore, since I have a manuscript partially completed I will not offer additional information on kyanite.  I just need to get a photo or two out for the readers.