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Post by nose2ground on Oct 10, 2008 16:10:47 GMT -5
at least for around here - found this today on the lake shore - it is basically quartzite, but is coated with a metallic-looking material - very shiny, depending on the angle has a bluish or purplish hue.  any ideas as to what it might be? Thanks! |
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Post by gsellis on Oct 10, 2008 16:58:40 GMT -5
Looks like Hematite. On Lake Lanier?
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Post by gemlover on Oct 10, 2008 17:30:26 GMT -5
again, need some properties
hardness?
streak?
feel?
could be a graphite layer, that has a silvery gray metallic luster.
John
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Post by nose2ground on Oct 10, 2008 18:50:58 GMT -5
yep, on Lake Lanier. I have found limonite after pyrite and magnetite in this area. None of it looks like this.
as for other info - gonna be hard to tell - it is a thin coating, which I can't get off - in areas looks like it is fused/blended into the quartz. So it appears to be on the harder side. Will streak test it in a bit and let you know (I'm eventually going to learn to do all that beforehand, my bad).
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Post by dwtdenver on Oct 11, 2008 9:58:00 GMT -5
maybe molybdenite?
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Post by nose2ground on Oct 11, 2008 18:19:52 GMT -5
will have to look that one up - thanks.
OK, other specs - hardness is still tough to tell, this stuff is actually blended through the quartz in thin layers. It is definitely not as hard as the quartz - I would say more than 5.5 (??).
color scratch - this was different. Apparently a purplish brown. The other metal I find here are either blood red or dark brown.
if this helps - found 2 rocks last year that were coated with this same stuff - when the wife saw them, she was insistent these had been in a fire (for Indian pottery) and had been "reduced" because of the color pattern (kinda iridescent).
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Post by gemlover on Oct 11, 2008 18:55:03 GMT -5
dwt has it  Your hardness is being affected by the quartz. Molybdenite on quartz. [glow=red,2,300][/glow] |
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Post by amythestguy on Oct 11, 2008 19:07:52 GMT -5
I am going to take a stab at this on and say ilmenite even though your streak doesn't say so but I don't trust certain streak tests
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Post by nose2ground on Oct 11, 2008 19:09:21 GMT -5
really? cool - thanks very much. This kinda comes close to a Dr. House diagnostic mystery.
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Post by scott on Oct 15, 2008 7:13:12 GMT -5
Move it next to a compass, if the needle moves very slightly then it's ilmenite, otherwise I'd say hematite.
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Post by nose2ground on Oct 15, 2008 21:13:52 GMT -5
thanks Scott - did not move a compass needle, also did not attract to a magnet.
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Post by eriktheawful on Oct 16, 2008 12:23:18 GMT -5
Could be a manganese oxide of some sort, they can be pretty hard up to 6 for the crystalized stuff, but I bet it is hematite. Lots of hematite up near north Lake Lanier.
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