Hyperspectral and Petro – Chemical Signatures Study on Corundum Bearing Litho-Units around Sringeri Area, Chikmagalur District, Karnataka, India

Most extensively sought after gem stones are the varieties belonging to the mineral groups of corundum and beryl. Ruby and variously colored sapphires are next only to diamond in properties and beauty. In fact, many connoisseurs value ruby much higher than diamond, as large, flawless and intensely colored rubies are much rarer in nature than large diamond. Precambrian basement rocks of Karnataka composed of active and dynamic geological settings with economic mineral deposits and variety of gemstones. Sringeri area comes to Chikmagalur district, it has six kinds of litho units with economically viable minerals including gemstones varieties particularly in contact zones of ultramafics, Banded iron formation, amphibolite schist with gneiss and metabasalt & amphibolite - metagabbro. Random samples were collected such as amphibolite, gneiss and corundum within basement crystalline rocks through GTC (Ground Truth Check). The study carried out by geological, petrochemical and Hyperspectral signature using advent high-tech tools of Spectro- Radiometer (Spectral Evolution SR-3500) instrument, DARWin SP.V.1.3.0 and GIS software's. The spectral signatures of the collected samples were derived in laboratory environment to achieve better accuracy. Hyperspectral (350-2500nm) were developed as works mainly on physico-chemical and optical properties of the litho units which help in mapping of precious gemstones at lithological contacts and mineralized zones. The present study aims to charactrize the spectral behavior of Corundum and associated rocks of the study area. Spectral radiometer instrument bring out diagnostic features on lithological contact for better discrimination of verity gemstones and altered minerals. The final results highlight the spectral characters of corundum in economic mineral industry and associated rocks for better mapping of Sringeri area of Chikmagalur district of Precambrian rocks and similar terrains of Karnataka State.