Polished Dugway Geode Half DX231 orange calcite 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

Malachite Rhinoceros Carving

This piece reacts to long-wave ultraviolet light

8" Septarian Slab

Polished Dugway Geode Half DX231 orange calcite The Tyndall effect is alsoDugway Geode Approx. Dimensions: 3. 5 x 3. 5 x 2" Approx. Weight: 474 grams Locality: Dugway Geode Beds, Juab County, Utah Includes three prong geode stand This piece reacts to short and long wave ultraviolet light, shown in the last two photos. Many portions of the inside of the geode glow a vibrant green. The fluorescence is due to trace amounts of uranium present in the quartz and chalcedony. Approximately 6 to 8 million years ago (Miocene epoch),