Ontario Mineral - Chondrodite

Monoclinic; complex aluminosilicate; glassy, shapeless or nearly shapeless grains in crystalline limestones.

Description:

Chondrodite is the most common and most well known member of the Humite Group of minerals. Members of the Humite Group are noted for having a mixture of silicate layers and oxide layers in their structures. The silicate layers have the same structure as olivine. The oxide layers have the same structure as brucite. In the case of chondrodite, there are two consecutive olivine layers that alternate between each brucite layer. The mineral humite, the next most common member of the group and the group's namesake, has three olivine layers between each brucite layer.Chondrodite is not a particularly common mineral and is never seen in abundance. It is found in hydrothermal deposits and contact and regionally metamorphosed dolomitic limestones, most notably skarn deposits and in some serpentinite rocks. Crystals when found are very complex with many competing forms adding many different and seemingly unrelated faces. Most often the individual crystals appear rounded or granular. This characteristic of individual grains lead to its name which is derived from a Greek word that means, "grain".