Colemanite Value, Price, and Jewelry Information
Colemanite is an abundant mineral, and transparent material isn’t rare. However, gem cutters rarely facet these typically pale stones. Difficult to cut and wear, colemanites are better suited for collectors of unusual gemstones.
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Colemanite is an abundant mineral, and transparent material isn’t rare. However, gem cutters rarely facet these typically pale stones. Difficult to cut and wear, colemanites are better suited for collectors of unusual gemstones.
What is Colemanite?
Colemanite serves as an ore for boron and has many industrial uses.
Does Colemanite Make a Good Jewelry Stone?
Colemanite has weak dispersion, so it shows little fire, and normally occurs colorless. Since it also has perfect cleavage and a hardness of only 4.5, this fragile gem would make an unlikely choice for a jewelry stone. Ring use would require a protective setting. Other uses, such as in earrings, pendants, or brooches, would be more practical.
Colemanites have considerable heat sensitivity, so jewelers should take great care placing these gems in metal settings.
Identifying Colemanites
Colemanites are both pyroelectric and piezoelectric. They generate an electric current when heated or placed under pressure, respectively.
Faceted colemanites may show facet doubling due to their birefringence.
This large, eye-clean, custom shield-cut colemanite displays the facet doubling effect very nicely. 9.33 cts, 14 x 12.1 mm, Boron, California. © The Gem Trader. Used with permission.
Are There Synthetic Colemanites?
Scientists have synthesized colemanites for a variety of research projects, including studies of their electrical properties. However, there's no known jewelry use for this lab-created material.
Colemanites don't usually receive any known gemstone treatments.
Where are Colemanites Found?
The southwestern United States, particularly Boron and Death Valley, California, produces beautiful colemanite crystals. Other notable sources include Argentina, Kazakhstan, and Turkey.
Stone Sizes
Large crystals and masses could yield gems of 50-100 carats. Crystals normally range up to about 1 inch in size.
- Smithsonian Institution (Washington, DC): 14.9 (California).
Caring for Colemanite
Colemanites are slightly soluble in water. Don't soak these gems during cleaning. Make sure to pat them dry before storing. Clean them only with a soft brush, mild detergent, and warm water. For more care recommendations, consult our gemstone jewelry cleaning guide.
Joel E. Arem, Ph.D., FGA
Dr. Joel E. Arem has more than 60 years of experience in the world of gems and minerals. After obtaining his Ph.D. in Mineralogy from Harvard University, he has published numerous books that are still among the most widely used references and guidebooks on crystals, gems and minerals in the world.
Co-founder and President of numerous organizations, Dr. Arem has enjoyed a lifelong career in mineralogy and gemology. He has been a Smithsonian scientist and Curator, a consultant to many well-known companies and institutions, and a prolific author and speaker. Although his main activities have been as a gem cutter and dealer, his focus has always been education. joelarem.com
International Gem Society
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