64g Optical Calcite Freeform TC2139 byssolite The Tyndall effect is also

The Tyndall effect is also the reason why blue chalcedony appears yellow or brown when strong light shines through it

Locality: Xiefang Mine

Weight: 323 grams

purple (amethyst)

64g Optical Calcite Freeform TC2139 byssolite The Tyndall effect is also64g Optical Calcite Freeform Approx. Dimensions: 1. 25x1x2. 25 inches Approx. Weight: 64 grams Locality: Maharashtra, India Optical calcite is also referred to as Iceland Spar because of its first discovery in Eskifjord, Iceland. It is typically colorless, and exhibits the optical phenomenon of double refraction where an object viewed through the calcite will appear doubled. Double refraction, or birefraction, is also called birefringence and is also