1.35" Beryl (Var. Emerald) in Calcite - Khaltoru Mine, Pakistan

This is a 1.35" wide specimen that contains an association of emerald in a mass of calcite. While the emerald crystals aren't large and/or well defined, the vibrant green color of this variety of beryl is present. It was collected from the Khaltoru Mine in northern Pakistan.

Beryl is a mineral that's 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 known to be the most rare form of beryl found, and is currently only known to be found in New Mexico and Utah.

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.
DETAILS
SPECIES
Beryl var. Emerald & Calcite
LOCATION
Khaltoru Mine, Northern Pakistan
SIZE
specimen is 1.35" wide
CATEGORY
ITEM
#112069