Monday, May 14, 2018

Dharwar Craton- Gooty Fort

I had quite a fruitful interaction today on Twitter, after I replied to a tweet about the location of Gooty Fort in Andhra Pradesh.

The fort is built on Archaean gneiss terrain just to the west of the Cuddapah sedimentary basin. I'm embedding the tweet below. It invoked quite a few questions about the terrain and the geology of that region.



And here is the link to the full discussion thread on Twitter - Gooty Fort, Andhra Pradesh

Monday, May 7, 2018

Green Apophyllite

Sigh.. I did a search for Green Apophyllite and most of the top returned links were websites about crystal healing and crystal therapy! :(


I wish Google would introduce a 'credibility metric' in their website ranking algorithm.

Apophyllite is a phyllosilicate (silica and oxygen tetrahedrons are organized in stacked sheets) . It occurs as a secondary mineral in the Deccan basalts, along with zeolites, quartz and calcite. The green color is due to trace amounts of vanadium. I wanted to confirm that. Instead, I got links to websites telling me that Apophyllite "opens the heart chakras and encourages the release of old emotional wounds".

The picture of green apophyllite that I have posted was taken at the Gargoti Mineral Museum near Nasik.