Aragonite is a
carbonate mineral with the same chemical composition as Calcite (CaCO3),
but its crystals are different, including prismatic, tabular, or
needlelike forms. Aragonite specimens can be white,
colorless, gray, yellowish, green, blue, reddish, violet, or brown.
Aragonite is found in the oxidized zones of ore deposits, and
also in evaporites, hot spring deposits, and caves.
The Aragonite specimens on this page come
from Morocco. They form radiating clusters of
reddish-brown prismatic twinned crystals, and are sometimes referred to
as "Sputnik Aragonite."
Aragonite is named after the Aragon River in Spain, where it was first
discovered. Many sea creatures secrete Aragonite to
make their shells, and pearls consist mainly of Aragonite.