8" Quartz Crystals With Adularia - Hardangervidda, Norway

 
 
 
 
This specimen contains an association of pristine quartz crystals and white adularia (variety of orthoclase). The crystals formed from a schist matrix that was collected from Hardangervidda, Norway.

There are several small twinned anatase crystal son what could be considered the bottom of this specimen, partially exposed from the schist matrix.

Silicon Dioxide, also know as SiO2 or Quartz, is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich, hot watery solutions called hydrothermal environments, at temperatures between 100°C and 450°C, and usually under very high pressure. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountains forming, and can be hundreds of millions of years old.

Adularia is a variety of feldspar that had the chemical formula KAlSi3O8. It's found most often as colorless to white aggregations within metamorphic rock, with one example being formation within cavities of crystalline schists. The crystals are commonly twinned, glassy and prismatic in structure, and in some cases they display opalescent characteristics. Adularia is very similar to orthoclase, even baring the same chemical formula, however it has a different crystalline structure and reacts differently to various tests.

Anatase is composed of titanium dioxide, and typically forms dipyramidal crystals, although variations can occur with mineral clumping. Four pointed X-shaped anatase crystals, while rare, have been found and are known as "X-shaped penetration twins". Horizontal striations can be seen across most anatase mineral faces, with most crystals ending in points, or with variations of flattening on each end.
FOR SALE
$395
DETAILS
SPECIES
Quartz, Anatase & Orthoclase var. Adularia
LOCATION
Hardangervidda, Norway
SIZE
8 x 5.9"
CATEGORY
ITEM
#111476