2.7" Feldspar, Aquamarine, Schorl and Quartz Association - Namibia

This specimen contains an aquamarine crystal, black tourmaline, small quartz crystals along one edge, all of which formed from feldspar. It was collected from the Erongo Mountains in Namibia.

The aquamarine crystal is small, measuring only .32" long.

Feldspars are a group of rock-forming tectosilicate minerals. They are the most common minerals on Earth, making up nearly 60% of the crust.

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.

Beryl is a mineral composed of beryllium aluminum cyclosilicate, with the chemical formula Be3Al2(SiO3)6. Naturally occurring beryl tends to form hexagonal crystals that can reach several meters in size if given the right conditions. Completely pure beryl will be transparent and colorless, while mineral impurities frequently tint the crystals color in most specimens.

Well known varieties of beryl include aquamarine and emerald, although beryl can also be green, blue, yellow, white and red, depending on the incorporated impurities during formation. Red beryl is its rarest form, and can currently only be found in New Mexico and Utah.

Tourmaline is a crystalline boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Schorl, or black tourmaline, is the most common form of tourmaline, and has been used for everything from jewelry to piezoelectric guitar pickups.
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DETAILS
SPECIES
Beryl var. Aquamarine, Black Tourmaline (Schorl), Quartz & Feldspar
LOCATION
Erongo Mountains, Karibib, Erongo Region, Namibia
SIZE
2.7" long
CATEGORY
SUB CATEGORY
ITEM
#96585