Hendricksite

Hendricksite can either form short prismatic crystals, or foliated ones that are platy and seem two dimensional. It occurs in clusters, It doesn't show any fluorescence under either shortwave, or longwave ultraviolet light. == Chemical properties ==

It mostly consists of oxygen (38.92%), zinc (18.56%), silicon (15.37%) and manganese (10.02%), but otherwise contains potassium (7.13%), aluminium (7.11%), magnesium (2.46%) and a negligible amount of hydrogen (0.41%). It has a barely detectable, 1% radioactivity measured by GRapi (Gamma Ray American Petroleum Institute Units) due to its potassium content, which gives the mineral its radioactive attributes. == Occurrences and localities ==

It can appear only in metamorphosed stratiform zinc deposits, in irregular lens or sheet like skarn bodies. It can be found in the Franklin mine in New Jersey, US. The mineral can be found at the Sterling hill as well, although it is much rarer due to the higher iron and magnesium concentrations. It occurs with vesuvianite, bustamite and feldspars, additional associated minerals being minerals of the axinite group, calcite, rhodonite, willemite, hancockite, as well as andrasite. == References ==