IGS Background

Holtite Value, Price, and Jewelry Information


This mineral was first noted in 1937 but was not described in detail until 1971. It has not yet been seen as a gem, but the high hardness would allow it be worn with no risk of scratching. Holtite is now considered to be a variety of dumortierite. The mineral comes from the one locality, and a cut stone would have to be considered a great rarity.

HomeGemstonesHoltite Value, Price, and Jewelry Information
By Joel E. Arem, Ph.D., FGA, updated on

Optics:a= 1.743-1.746;  β= 1.756-1.759; γ= 1.758-1.761.

Biaxial (-), 2V= 49-55°.

Occurrence: Alluvial tin deposit near Greenoushes, Western Australia, associated with cassiterite.

Comments: This mineral was first noted in 1937 but was not described in detail until 1971. It has not yet been seen as a gem, but the high hardness would allow it be worn with no risk of scratching. Holtite is now considered to be a variety of dumortierite. The mineral comes from the one locality, and a cut stone would have to be considered a great rarity.

Name: After Harold E. Holt, prime minister of Australia from 1966 to 1967.

Never Stop Learning

When you join the IGS community, you get trusted diamond & gemstone information when you need it.

Become a Member

Get Gemology Insights

Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!