Tephroite
Tephroite

Tephroite Value, Price, and Jewelry Information


Tephroite is generally reddish brown and barely translucent. However, it takes a good polish and is massive enough to make good cabochons. Only the New Jersey and Australian localities seem to have provided such material, however. Faceted gems are unknown.

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Tephroite is generally reddish brown and barely translucent. However, it takes a good polish and is massive enough to make good cabochons. Only the New Jersey and Australian localities seem to have provided such material, however. Faceted gems are unknown.

Tephroite
Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0], via Wikimedia Commons

Streak: pale gray.

Optics:a =1.770-1.788; = 1.807-1.810; =1.817-1.825.

Biaxial (—).

Occurrence: In iron-manganese ore deposits and associated skarns.

California; Colorado.

Franklin and Sterling Hill, New Jersey: cuttable.

England; Sweden; France; Japan.

Tamworth. NS.W. Australia: small Mn deposits with massive tephroite streaks in rhodonite.

This material is suitable for cabochons.

Comments: Tephroite is generally reddish brown and barely translucent. However, it takes a good polish and is massive enough to make good cabochons. Only the New Jersey and Australian localities seem to have provided such material, however. Faceted gems are unknown.

Name: From the Greek tephros, meaning ash colored.


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

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