Rockin the Rockies

Rockin the Rockies
Stowe Mtn

Friday, October 12, 2012

Microcline In The Lake George Intrusive Area

When I prospect the area north and east of Lake George I'm normally either looking for amazonite, fluorite or smoky quartz crystals. One of the indicators I use to know I'm onto something is microcline. I figure if there is microcline crystals present, then I'm probably rooting around in a pegmatite that might also produce quartz crystals or other desirable specimens. Normally I leave the microcline at the dig. While they are crystals, they are rather plain when compared to their brilliant blue/green cousins amazonite. When I'm having a slow day prospecting, I might take home an occasional well-formed microcline specimen. Last month I was digging out some fairly nice smokys when I hit some microcline crystals. These microcline crystals were rather odd in shape, so I dug them up, pursuing them 6 feet into the ground and took them home and cleaned them up. While cleaning I noticed they were twins. I knew they were both manebach and bevino twins. The easiest way to detect twins is to look for V-shaped reentrys between crystals. You can also detect cross hatched banding on the crystal faces indicating where one crystals starts and the other leaves off. I didn't think a lot about the crystals, but took them to my mentor, Ray Berry, who has been digging out pegmatites for over 40 years. Ray likes odd things and these seemed out of the ordinary to me. Ray was quite impressed with the crystals. Ray thought some of the microcline crystals might be double or even triple twins. He told me a feldspar collector would kill for these, so I decided not include my home address in this blog ;-)
Bevino and Manebach (V reentry on bottom)

V-Reentry clearly visible with Bevino hanging off side

Bevino twin on lower right, albite on left side