Aragonite is found only in basalt rock in a few places around the world, including Taiwan's Penghu islands. Aragonite from Taiwan Penghu is considered the most beautiful and has the richest colors. Yellow and brown are the most common colors with a shape similar to a cluster of grapes. Some Aragonite form the "Aragonite Eye", a concentric circlular pattern, after polishing.
Mineral Formation Penghu's aragonite is formed in cavities within the basalt. During volcanic eruptions in the Miocene Epoch, gases in the lava expand as the pressure and temperature drops forming air holes in the basalt. Water then carries dissolved minerals into these spaces where they gradually accumulate over time. The crystals which form from the calcium, magnesium, iron and silicon deposits are known as "aragonite".
Applications Ornamental semi-precious stone, decorations and personal seals.