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Question
blue stone
blue stone  
Hello. I have recently received a necklace a with a blueish stone.I would like to ask to identify the rock for me. I Have tried researching on my own but i had no luck.Geoligy is a field that has always interested me and I would like to learn more about it.Could you please tell me its specific name and location where it could be found?
Thank you in advance.

Answer
Hi Patricia,
Very nice pendant!  You asked about the "blueish stone" but since both are blue I am not sure which you want information about......so I'll talk about both.

The big one is called "Labradorite".  It's a plagioclase feldspar mineral made up of mostly the variety "Anorthite".  It's pretty hard and not terribly common but its claim to fame is the way it displays an iridescence when the light hits it correctly and on the right surface (labradorescence).  Its type locality is Labrador, Canada, and its primarily used for jewelry.

This site shows pretty spectacular specimens but something like yours;
http://onetribe.nu/workshop/labradorite

These show a lot more than you might want to know.  The second one includes locations where found labradorite is currently found;  
http://www.minerals.net/mineral/labradorite.aspx
http://www.mindat.org/min-2308.html
http://en.wikipedia.org/wiki/Labradorite


Now for the other blue stone; I'm not sure what it is.  Amazonite can be blue like that but your stone doesn't look like it has the striations of exsolved albite that you'd commonly find in it.  Here's a site with some info;

http://en.wikipedia.org/wiki/Amazonite

Here's one with a picture of amazonite but the blue doesn't seem quite right and is too clear
http://www.gemselect.com/amazonite/amazonite-268322.php

That leads me to think it might be microcrystalline quartz or chalcedony.  

This site shows a sample of chalcedony with color and surface similar to yours;
http://luminajewellery.com/shop/blue-chalcedony-oval-twist-ring/

The last thing I think it could be, is plastic.  Just not sure without analysis.

Hope this helps.
Bob  

Geology

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C. Robert Reszka, Jr.

Expertise

I can answer any general geology question (rocks, minerals, stratigraphy, geomorphology etc.). My expertise is in the geology of the Michigan Basin, PreCambrian, Paleozoic and Recent. I can answer questions concerning mining and petroleum exploration and production and the laws concerning those activities. I can also answer questions concerning stratigraphy of the Michigan Basin. I will also answer questions about mineral and rock collecting in the Basin. I won`t be able to answer many specific questions on hydrology, geophysics or geochemistry. I may be able to answer very general questions in those venues.

Experience

I have been working for the State of Michigan for 36 years as a Geologist and a Resource Analyst. I have experience with Subsurface Geology and Petroleum Geology, mining in Michigan, and Sand Dune Mining and Protection issues.

Organizations
Michigan Basin Geological Society

Publications
Decade of North American Geology.
Bedrock Geology of Michigan

Education/Credentials
BS Wayne State University

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