shield-cut bytownite - Mexicoshield-cut bytownite - Mexico

Bytownite Value, Price, and Jewelry Information

Although bytownite occurs throughout the world, this feldspar variety is rarely encountered in gem-quality condition.

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HomeGemstonesBytownite Value, Price, and Jewelry Information

Although bytownite occurs throughout the world, this feldspar variety is rarely encountered in gem-quality condition.

shield-cut bytownite - Mexico
Brilliant shield-cut bytownite, 21.34 cts, 26.7 x 18.1 mm, Mexico. © The Gem Trader. Used with permission.

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Bytownite Value

Bytownite, 2.5 x 1.9 cm, Dorado Mine, Casas Grandes Municipality, Chihuahua, Mexico. Photo by John Sobolewski. Licensed under CC By 3.0.

What is Bytownite?

Bytownite is part of the plagioclase feldspar solid solution series. It has a composition closer to calcium-rich anorthite than sodium-rich albite, about 70-90% to 10-30%, respectively. Bytownites occur in a great variety of rock types and environments, However, transparent crystals are rare.

Does Bytownite Make a Good Jewelry Stone?

Some plagioclases, like labradorite, make popular gemstones. Nevertheless, with a hardness of 6 to 6.5 and perfect cleavage in one direction and good or imperfect in two others, bytownites are still susceptible to damage from scratches and blows against hard surfaces. As ring stones, bytownites would need protective settings. Use for earrings, pendants, and brooches would be more advisable.

rare gem pendant
This 18K gold brooch/pendant features a 3.31-ct bytownite as the butterfly's body. Sapphire, boulder opals, Gilson opals, kornerupines, and diamonds comprise other parts. Goldsmith, André Enskat; engraver, H. Postler; gem cutter, H. Lorenz. Photo courtesy of and Henry's Auktionshaus AG.

Are There Synthetic Bytownites?

There are no known synthetic bytownites or treatments for natural specimens.

Where are Bytownites Found?

Chihuahua, Mexico produces gem-quality bytownites.

In the United States, reddish bytownite pebbles from Arizona and New Mexico have been faceted into small gems. Bytownites have also been reported from Plush, Oregon, a well-known locality for facetable labradorite crystals. Some of these feldspars may have a borderline composition and cross over into the bytownite range.

Other notable gem-quality sources include the following:

  • United States: Minnesota; Montana; Oklahoma; South Dakota; Wisconsin.
  • Japan; South Africa; Sweden; United Kingdom: England, Scotland.
bytownite - Minnesota
Bytownite, Crystal Bay, Minnesota. Photo by Dave Dyet. Public domain.

How to Care for Bytownites

Due to their cleavage, avoid cleaning bytownites with mechanical cleaning systems, like steam and ultrasound. Clean them only with a soft brush, mild detergent, and warm water. Consult our gemstone jewelry cleaning guide for more recommendations.

bytownites - rough and cut set, Mexico
Rough and cut set, bytownites, 3.2 x 2.3 x 1.6 cm (crystal),14.23 ct (cushion step-cut gem), Chihuahua, Mexico. © Rob Lavinsky, Used with permission.

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.

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