#olite

Royal Palace of Olite

Olite, Navarre (Spain)

The Deccan: The Kingdom of the zeolites

During the creation of the Himalayan mountain range, an enormous expanse of basalt formed to the south as a result of a long period of volcanic activity. This geological formation contains huge cavities full of mineralised deposits.

The Deccan occupies most of India’s Maharashtra state. It is an enormous basalt plateau, which in some places is 20km (12miles) thick. Of the 1,500,000 km2 covered by this plateau at the end of the Cretaceous period, about 500,000 km2 remain today, forming a beautiful landscape of hills, gorges and plains, covered with meadows and forests, extensive cultivated areas and some virtually uninhabited regions. It is also home to many large cities, including Mumbai (Bombay).

The wealth of minerals in the Deccan, and the diamonds and aquamarines of its Padyur region, have been known for hundreds of years, Cities such as Pune, Nasik, Whagoli, Pandulena, Lonavala, Ahmednager and Aurangabad have all traded gems since time immemorial. The Temple of Kailasa, carved directly out of an immense basalt of a trapp step of living rock is part of the Ellora Cave complex in Maharashtra. The rock is part of the enormous expanse of basalt that accumulated in the Deccan over a period of 5 million years.

The term zeolite is used to denote minerals that generally form after basalt from fluids in vesicles. Zeolites comprise a group of silicates (tectosilicates) with hollows or channels within their crystal structure, giving them their characteristic properties. The Deccan probably has more zeolites than anywhere else in the world. These minerals, which until just a few decades ago aroused little interest, have recently gained a new importance, primarily in the fields of industry and medicine. Some of them are abundant in the region and are characterised by the beauty of their crystal forms—for example, cabasite, heulandite, laumonite, mesolite (which occurs as very beautiful clusters of needle-shaped crystals), natrolite, ferrierite, scolecite, stilbite and okenite, (which looks like balls of cotton wool). Others, such as epistilbite, goosecreekite, amicite and yugawaralite, are rarer.

The Deccan also has minerals of other groups, including fluorite with a red or yellow colour and found in a rare and strange spherical form. Calcite appears as crystals of extraordinary clarity, and powellite, a rare calcium molybdite, (a compound containing an oxoanion with molybdenum in its highest oxidation state of 6) forms astonishing bipyramidal crystals that are without doubt the best in the world (post pic).

~ JM

Image Credit: (Main Pic) http://bit.ly/1EN3qHN (powellite) http://bit.ly/1yn6nwc