This is the transparent beryl pebble (aquamarine). Weight – 0.1oz (4 grams). Origin: Russia, Transbaikalia.
Some information about beryl:
In geology, beryl is a mineral composed of beryllium aluminium cyclosilicate with the chemical formula Be3Al2(SiO3)6. The hexagonal crystals of beryl may be very small or range to several meters in size. Terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, red, and white.
The name beryl is derived from Greek beryllos which referred to a «precious blue-green color-of-sea-water stone».
Beryl of various colors is found most commonly in granitic pegmatites, but also occurs in mica schists in the Ural Mountains, and limestone in Colombia. Beryl is often associated with tin and tungsten ore bodies. Beryl is found in Russia, in Europe in Norway, Austria, Germany, Sweden (especially morganite), Ireland, as well as Brazil, Colombia, Madagascar, Mozambique, South Africa, the United States, and Zambia. US beryl locations are in California, Colorado, Connecticut, Idaho, Maine, New Hampshire, North Carolina, South Dakota and Utah.
Varieties of beryl: aquamarine and maxixe (blue and deep blue beryl), emerald (green beryl), heliodor (yellow beryl), goshenite (colorless beryl), morganite (pink beryl), red beryl.