Dogtooth Calcite and Mariposa Calcite
Dogtooth Calcite is a variety of Calcite that forms as multiple scalenohedral crystals. Dogtooth Calcite is often referred to as Dog-toothed Spar. (Spar is a general term for transparent to translucent, generally light-colored and vitreous crystalline minerals.) Dogtooth Calcite is an unusual variety of calcite and is named "Dogtooth" because the stone itself looks like a large collection of dogs teeth. It has some standard colorings from clear through golden, white, grey, tan, brown and purple to name a few, but also is found some rarer shades.
Dogtooth Calcite is often found in caves as a speleothem growing out of limestone. These caves often have standing water that is seasonal or undisturbed for many years to allow these unique formations to grow. Dogtooth calcite crystals are not limited to caves, but can grow in any open space including veins, fractures, and geodes.
The sharply tooth-shaped crystals typically consist of acute scalenohedrons, triangular crystal faces that ideally form scalene triangles. (In a scalene triangle, all sides and all angles are unequal. An example is a right triangle, but scalene triangles are not always right triangles.) However, modification of these faces is common, and individual crystal faces may have many more than three edges.
Our favorite Dogtooth Calcite specimens come from the Mines in the Santa Eulalia District, Chihuahua, Mexico. The stunning tans, browns, purples and "snow coatings" are fascinating
Mariposa Calcite (Butterfly Calcite)
Calcite from the Mariposa Mine gained fame for having a phosphorescence more brilliant than it's fluorescence...under SW Ultra Violet light the bright red fluorescence is almost immediately lost by the occurrence of a brilliant bluish-white phosphorescence...the true Mariposa Calcite is actually from the Mariposa Mine (California Mountain Mine), Terlingua District, Brewster Co., Texas, USA
Today what is now called Mariposa Calcite is characterized by alternating overgrowths of dogtooth calcite and hematite that create beautiful phantoms and inclusions. The true Mariposa (butterfly) Calcite has not been found for almost 50 years. Under UV SW the areas of white calcite glow bright red. The calcite that glows like fire on these specimens is found on the bottom and sides of the specimen. The area of crystal points has only a few spots that fluoresce. What people love about Mariposa Calcite is that it is a great looking specimen even without the UV lamp.
The miners currently have to go on a two or three day trip into the mine to get these "Mariposa-like" specimens. It is dangerous work and we feel it's just amazing to have any of them for our collection. Our supply of "Mariposa Calcite" is mined at the 20th level of the Potosí Mine, located in the Santa Eulalia District, Aquiles Serdan, Chihuahua, Mexico. These specimens have excellent Scalenohedral (dogtooth) calcite crystals with phantom hematite inner red and maroon crystal formations in a clear to orange tinted calcite. These Potosí Mine specimens are some of the nicest "Mariposa Calcites" available on the market today