2.28" Bi-Colored Aquamarine Crystal - Transbaikalia, Russia

This is a 2.28" long, bi-colored beryl (aquamarine) crystal that was collected near Transbaikalia, Russia. The color at the base of the crystal is sky-blue, abruptly shifting to green and then transitioning to a faint-green approaching the termination. Blue growth lines/layers can be seen throughout the green portion of this crystal.

This specimen has been mounted to an acrylic display base.

Aquamarine is a blue-green variety of beryl. Oddly enough, it owes its color to iron(II) and iron(III) cations within the crystal lattice, of which iron(II) is responsible for the blue color, while iron(III) is responsible for the yellow color. The color vibrance and hue are dependent on the concentration of these cations, or lack of one or the other. The presence of both cations in the right position within the crystal lattice, can result in a deep blue colored crystal that is known as "maxixe".

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.
Beryl var. Aquamarine
Transbaikalia, Russia
2.28" long