Tuesday, July 23, 2013

Alkaline mineralogy in everyday life.

Some alkaline minerals play an important role in our everyday life. Considering my kitchen as an alkaline province I decided to look closer at one the main constituent. Baking powder is made up of sodium hydrocarbonate (NaHCO3) and its natural analogue is nahcolite. Since the powder I used is a loos aggregate of short-columnar crystals the microscope is not very useful. Thus the sample has been dissolved in water and then dried down in microwave. Due to short crystallization time nahcolite formed spherulites which demonstrate typical cross-like extinction in cross polarized light.

Friday, July 19, 2013

Obsession - s/t 2013. Everything gets involved.

First of all, I am sorry to post this so late. The album came out 4 month ago.
I am happy to show the world the interaction of Music and Geosciences. The Obsession's new album came out in March, 2013. I am proud to see my picture on the cover of album. I am grateful to my best friends/bandmates for their support,  for playing the music and being with me. 
Listen and download (free) music: http://obsessionhc.bandcamp.com

I would like to give a short explanation. Basically, this pegmatitic rock (microclinite) consists mostly of large (>10cm) microcline-perthite crystals. Rarely, anhedral grains of albite (not perthite) could be found embedded in microcline. On the picture you see: gray irregularly colored mass - microcline; two striped bends across the picture - perthites; black-white crystal in center - albite.

The most interesting fact is that central albite grain is, most likely, relict from alkali granite that existed here before the rock turned into microclinite. Since the relict grain is more calcic, it shows higher relief than perthite bends. More "scientific" look:

Mc-microcline, Ab8 - relict albite, Ab2-3 - perthitic albite. XPL (crossed Nicols)
The rock location: Gremyakha-Vyrmes alkaline complex (1.8 Ga), Kola peninsula, Russia

Don't let be science boring!