Earth Treasures: Datolite
By Chisom Ibemere
Datolite mineral is a calcium boron hydroxide nesosilicate which was first noticed by Jeus Esmark, a Danish-Norwegian geologists in 1806. It is made up of sheets of 4-8 membered rings and is known as the second mineral in the gadolinite supergroup.
Datolite is gotten from the Greek word, “dateisthai” which means to “divide”. This is due to its ability to crumble easily.
Datolite has the ability to crystallize in monoclinic system which leads to the formation of nodular masses and prismatic crystals. It has a vitreous lustre with varieties of colours such as yellow, brown, green and may be colourless. It has a specific gravity of 2.8-3.0 with a mohs hardness of 5.5. It’s associated with some other minerals such as Calcite, Zeolites, quartz, danburite and most common in Lake region of Michigan in Copper deposits. It is found as a secondary mineral in Igneous rocks and usually found in vessels together with basalt and Zeolites. It’s occurrence in Lake superior of Michigan is usually in form of fine grain with bands of colours. It’s colouration occurs as a result of it’s inclusion of copper in hydrothermal precipitation.
Datolite mineral serves as a source of boron and are seen mostly in mineral collections rather than in Jewelries. They may also give rise to or used in the production of Cabochons. Datolites when used in addition with copper brings about striking and attractive colours.
Datolite give off fluoresce when exposed to shortwave ultraviolet light. They may be used to improve boron prospecting efficiency by using it’s luminescence.
Datolites may be cut in different sizes. The largest may measure up to 5 carats. Larger stones are relatively rare. They may easily scratch when kept together with other harder stones.