GEM NOTES

RHODOCHROSITE

Çig ˘ dem Lüle , PhD., FGA, GG (GIA)

hodochrosite has been used as an ornamental ma - terial for carvings, beads and inlays due to its low Rhardness, for a very long time. Beautiful pink color contrasting with white banding in massive form is the typ - ical appearance of the material. The Sweet Home Mine in Colorado, however, has been known for its stunning, transparent single crystals suitable for faceting since the 1800s. More economical mining techniques of the later part of the 20 th century made the transparent red rhodochrosite a collector’s gem.

Rhodochrosite is a manganese carbonate mineral (MnCO 3) with low hardness of 4 and three directional per - fect cleavage. Despite its low durability, transparent red crystals are faceted and used in jewelry. Transparent rhodochrosite is highly sought after by collectors, espe - cially when they come from Colorado’s Sweet Home 21.86 ct. Rhodochrosite from Sweet Home Mine, Colorado. Courtesy of Mine. There are other transparent rhodochrosite sources Mayer and Watt. Photo by Geoffrey Watt. such as the Kalahari region in South Africa and the Pal - lasca Province in Peru. However, neither of these sources Collectors are aware that Sweet Home Mine demands a pre - has provided regular production. On the other hand, the mium, yet the deeper red stones from South Africa may be massive form of rhodochrosite is produced in many local - as expensive since the source is diminishing now. China pro - ities in the world, most notably Argentina. Other localities duces nice transparent pink material at more affordable lev - include Romania, Germany, New South Wales in Australia, els but less than $100 price point is unheard of. Tasmania, Mexico and China. While transparent red faceted rhodochrosite is sold at Rhodochrosite pricing varies widely based on its form. It is higher per carat prices, the massive form is generally sold rare, so faceted rhodochrosite is usually only available from by per gram in most cases, per piece when it is a carving, dealers that specialize in the collection grade gems. Smaller or per strand for beads. Buyers need to be aware of simu - sizes, around one carat, starting around $100 per carat may lants such as glass or resin since the pretty pink color with go up to $250 to $300 per carat in fine quality from the white banding is easily imitated in carvings and beads. Sweet Home Mine. Since rhodochrosite is a challenging Also, another massive gem material rhodonite with similar stone to cut due its low durability, larger stones are much color pink is confused with rhodochrosite but standard rarer and may get priced as high as $800 to $900 per carat. gemological testing should resolve that issue. u

Gemworld International, Inc., 2640 Patriot Blvd, Suite 240, Glenview, IL 60026-8075, www.gemguide.com © 2017 Gemworld International, Inc. All rights reserved. All articles and photographs that appear are copyrighted by the author, the contributing person or company, or Gemworld International, Inc. and may not be reproduced in any printed or electronic format, posted on the internet, or distributed in any way without written permission. Address requests to the editor-in-chief. The opinions expressed in this publication are the opinions of the individual authors only and should not necessarily be considered to be the opinions of the staff of Gemworld International, Inc. as a whole. Any website listings that appear in articles are for informational purposes only and should not be considered an endorsement of that company.

GEMGUIDE - 1 - NOVEMBER / DECEMBER 2017