January 24 Through February 4—TUCSON, ARIZONA: Annual show
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PostPosted: Thu May 07, 2009 8:08 pm 
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I live in San Francisco and didn't know there was much around here. A friend of mine joined the SFGMS and is going on a trip with them to a turquoise mine in Nevada. It sounds fun. I'm thinking of joining too just for the local classes.

P.S. I found quartz in my yard.


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PostPosted: Thu May 07, 2009 8:18 pm 
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Location: South Dakota
ya know the san fran bay area is one on the most complex geological places on earth. My aunt sent me a book all about the geology of that area when she visited last year. Holy cow..it was an extremely indepth and complicated study of the different rocks and types and formations of that area. Not much in the way of gems but a geologist mecca! You should see the color coded map of the different rocktypes and stratas..it's like a picasso painting.

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PostPosted: Thu May 07, 2009 9:08 pm 
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Location: Southern California, U.S.A.
Jason,

San Francisco is cosmopolitan geologically as well as culturally. I strongly recommend John McPhee's wonderful book "Assembling California" to anyone with curiosity about our state's amazing geological past. Like all McPhee's geology-oriented books, it reads like a novel and is a cornucopia of fascinating geological information.

Much of the San Francisco region is made up of terranes from all over the earth that smacked into California's coast over a huge timespan thanks to plate tectonics. It makes for jigsaw-puzzle geology. And those processes are all linked to similar ones covered in two other of his absorbing books: "Basin and Range" (Nevada and Utah) and "Rising from the Plains" (Wyoming). A boil-down of all 3 is contained in his "Annals of the Former World."

Enjoy!

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PostPosted: Sat May 30, 2009 11:40 pm 
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Location: northern ca
Clear Lake Gem Mining Company of Woodland, California, considerable exploration and development work on a “gemstone” prospect in the SE1/4 of the SE1/4 of sec. 20, t. 12 N. R. 7 W., in 1929. Two large open cuts ( 100 feet log by 10 feet wide by 5 feet deep, and 200 feet long by 20 feet wide by 5 feet deep) and numerous smaller pits were cut in the Perini Hill andesite in search of gem material. The stones, a very clear, high-temperature variety of quartz, occur as irregular masses sprinkled through the andesite. These were originally thought to be hyalite, a variety of opal. Purple cordierite which originally was thought to be amethyst, is also present

Here’s the latitude / longitude numbers for Google Earth 38.868571° -122.652494


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PostPosted: Sun May 31, 2009 4:19 pm 
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red dirt, how old is that data?.. Perrini hill used to be a collecting site, but I understand the winery shut that down.

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PostPosted: Sun May 31, 2009 4:32 pm 
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Location: San Francisco
I guess, one way or another we could find something to do there. Image


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PostPosted: Sun May 31, 2009 6:11 pm 
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I'll bring the corkscrew, the bruschetta w/goat cheese, roasted red peppers and black truffles. Maybe a pyramid of fluted champagne glasses filled with "Dom" and a generous tray of chocolate covered strawberries and smoked Gouda cheese.

Just don't touch my flask. (Whadda ya think I'm made of money?) :)


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PostPosted: Sun May 31, 2009 6:35 pm 
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smoked Gouda cheese


I knew I smelled something good... when, where, how...?


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PostPosted: Sun May 31, 2009 6:49 pm 
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Location: northern ca
It came from Geology of Lower lake quadrangle, California bulletin 166 1953.
http://www.archive.org/details/geologyo ... 00bricrich
page 70 the cuts might still be visible on the hill next to the grapes.


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PostPosted: Sun May 31, 2009 8:32 pm 
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I knew I smelled something good... when, where, how...?


Tim, don't go all Vinnie Barbarino on me. If you get the invitation with the Gold ribbon, you're in.

If you get the invitation with the Silver ribbon, well, then it's cold cuts and a punch bowl.

Charitable contributions (to me) are considered before invitation mailings. :)


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