Aragonite

Info: Aragonite often crystalizes with orthorhombic structure, usually in the form of pointy crystals, which are often part of agregates. Sometimes aragonite can form up to six gemini crystal forms. Aragonite is usually colourless and transparent, but often is only translucent with various colouration. Aragonite have glassy to pitchy shine, its harder than calcite. Aragonite have many variations - the most famous is the so-called iron flower, which is often found in iron deposits, other variants are pistolite, tarnowzite and nicholsonite.

How to recognize: Aragonite is dissolved in hydrochloric acid, in this dessolvion it emits fizzing sound. In UV-light aragonite emits typical flourescence, which can be blue, pink or yellow. Aragonite is unstable mineral - in normal conditions slowly transforms into calcite. This transformation is catalized by heat.

Found: Bigger deposits of aragonite were found in Germany, Austria, Spain and Poland. In Czech Republic beautiful crystals of aragonite were found in Hřídelec u Nové Paky, Hořenec u Bíliny and in other locations.