1.4" Stilbite, Quartz, Clinozoisite and Calcite Association - Poland

This is a beautiful, 1.4" wide stilbite, smoky quartz, clinozoisite and calcite association that was collected from Strzegom, Poland. The stilbite is orange-brown in color and formed from a smoky quartz, clinozoisite and calcite crystal encrusted matrix. The smoky quartz can be found on what could be considered the underside of the specimen.

Stilbite is a tectosilicate mineral of the zeolite group that is commonly found in zeolite deposits. Crystals often form flowery bowtie or hourglass-shaped structures and come in a variety of colors. Some of the most beautiful colorations are the pink or peach tints.

Smoky quartz is a grey-brown to black variety of quartz. This common name is derived from the appearance of smoke within the quartz crystal. Depending on the location and the chemicals present during formation, smoky quartz can appear opaque black, but it is typically translucent to some extent. It is believed that the quartz gains this color from a combination of natural irradiation and aluminum impurities.

Quartz is the name given to silicon dioxide (SiO2) and is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich environments--usually igneous rocks or hydrothermal environments like geothermal waters--at temperatures between 100°C and 450°C, and usually under very high pressure. In either case, crystals will precipitate as temperatures cool, just as ice gradually forms when water freezes. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountain formation: these veins can be hundreds of millions of years old.

Clinozoisite is a aluminum calcium sorosilicate with the complex chemical formula {Ca2}{Al3}(Si2O7)(SiO4)O(OH). It is a member of the epidote group and is often found exhibiting colorless, yellow, yellow-green, green, or pink coloration. It also goes by the name of "aluminum epidote" and is found in locations of metamorphism and calcium-bearing sedimentary rocks.

Calcite, CaCO3, is a carbonate mineral and the most stable polymorph of calcium carbonate. The other polymorphs are the minerals aragonite and vaterite. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals. However, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, and prisms. Calcite exhibits several twinning types adding to the variety of observed forms. It may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form.
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DETAILS
SPECIES
Stilbite, Quartz var. Smoky, Clinozoisite & Calcite
LOCATION
Strzegom, Strzegom-Sobótka Massif, Poland
SIZE
1.4" wide
CATEGORY
ITEM
#148421