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Garnet?
May 6, 2012 22:18:10 GMT -5
Post by nichwhitt on May 6, 2012 22:18:10 GMT -5
Its hard to see in the photo, but the shiny area is blood red and transparent. Is there an easy way to distinguish if its garnet or ruby? Attachments:
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Post by rockshine on May 7, 2012 5:54:25 GMT -5
Ruby usually has at least one perfectly flat surface/face and an overall hex shape. Some ruby will fluoresce under long wave UV light. Also the matrix shown there seems to be quartzy/feldspar/pegmatite which is more conducive to garnet.
Still not telling where specimens are collected, unless asked?
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Post by nichwhitt on May 7, 2012 7:39:09 GMT -5
Very informative, thank you. Collected in MN.
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Garnet?
May 7, 2012 11:59:12 GMT -5
Post by rockshine on May 7, 2012 11:59:12 GMT -5
I found one report of corundum occurring in Minnesota, but didn't find the loacality, yet. Fiund out that the 3M company started mining operations at Corundum point, but it wasn't corundum, after all. Garnet is mentioned frequently in Minnesota geology, as is Mica, (Probably the green around the other photo, and a peculiar brown quartz is mentioned.
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Garnet?
May 7, 2012 12:25:13 GMT -5
Post by nichwhitt on May 7, 2012 12:25:13 GMT -5
"peculiar brown quartz" eh? Wonder what that means exactly? The other green rock doesnt seem to have the cleavage like mica, but I'm still a rookie. Thanks for the great info!
Didnt realize 3m was in the mining business, heh...
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Garnet?
May 7, 2012 13:36:39 GMT -5
Post by nichwhitt on May 7, 2012 13:36:39 GMT -5
Garnet and olivine in the area, although I have yet to find the latter...
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Garnet?
May 7, 2012 16:03:19 GMT -5
Post by leonardo on May 7, 2012 16:03:19 GMT -5
Minnesota Mining and Manufacturing...One thing they manufacture .is sandpaper...garnet....
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Garnet?
Oct 11, 2012 7:13:22 GMT -5
Post by yurash on Oct 11, 2012 7:13:22 GMT -5
Folks, garnet has hardnes from 6.5 to 7.5 by Mohs scale, as ruby has 9. This is a big difference!
It is easy to distinguish them by scratching (as long as you have topaz to spare).
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