OKENITE, ARAGONITE GEODE

Okenite (CaSi2O5·2H2O) is a silicate mineral typically found in association with zeolites. It is primarily discovered in small, white, cotton-like formations within basalt geodes, consisting of clusters of straight, radiating, fibrous crystals that exhibit both flexibility and fragility. Additionally, Okenite is classified within the family of calcium silicate hydrates (C-S-H), which are commonly present in hardened cement paste. In cement chemist notation (CCN), it is represented as CaO·2SiO2·2H2O and abbreviated as CS2H2.

Aragonite is a carbonate mineral and ranks among the three most prevalent natural crystal forms of calcium carbonate (CaCO3), alongside calcite and vaterite. It is produced through both biological and physical processes, primarily through precipitation in marine and freshwater settings.

The crystal structure of aragonite is distinct from that of calcite, leading to a unique crystal morphology characterized by an orthorhombic system and acicular crystals. This mineral often exhibits repeated twinning, which can create pseudo-hexagonal shapes. Aragonite may appear in columnar or fibrous forms and can occasionally take on branching helictitic shapes known as flos-ferri, named for their connection to the ores found in the Carinthian iron mines.