Chocolate dogtooth calcite, large Ferruginous quartz coronadite

coronadite

UV reactivity The small amount of hyalite will react a strong yellow-green color under 395nm UV or 365nm UV light

some displaying the Mercedes termination characteristic of the Erongo region

and produces long barrel-shaped hexagonal crystals

specimens may stain surfaces or leave residue when handled

Chocolate dogtooth calcite, large Ferruginous quartz coronaditeLocale: Santa Eulalia, Chihuahua, Mexico Approx size: 3. 75 x 2. 25 x 2. 25" Approx weight: 485g (about 1 lb) Known by the trade name "chocolate dogtooth calcite," this type of calcite from the famed Santa Eulalia mining district grows in hedgehog clusters of sharp dogtooth (scalenohedral) crystals. The variety gets its distinctive opaque brown appearance from iron oxides; a layer of hematite included calcite is deposited on the surface during a later