showet
Cave Dweller 
Member since June 2015
Posts: 65 
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Post by showet on Aug 20, 2015 17:54:59 GMT -5
A friend of mine picked up some rocks when he was over seas but he is not sure now where each of them came from, (Epypt, Iran, etc.) but somewhere in the middle east. He has asked me to cut them but I want to make sure they are what I think they are before I cut them. They are hard , probably 6 or more and heavy. I can't really see what is inside of any of them. I am pretty sure the first two are agates but the third I am not sure about. What think ye all? Suggestions for cutting?    |
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Post by vegasjames on Aug 20, 2015 18:27:56 GMT -5
Can you flat lap an area of the first two so I can see the inside?
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showet
Cave Dweller
Member since June 2015
Posts: 65
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Post by showet on Aug 20, 2015 18:53:56 GMT -5
Since they are not my rocks I hesitate to do anything to the outside because he was hoping to keep the out side natural and have a clean polished cut on the flat sides. As a last resort I can ask him if that would be OK but I would hope that is not necessary. I will wait a bit and see if there are other thoughts.
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Post by vegasjames on Aug 20, 2015 19:30:26 GMT -5
Are the first two magnetic? Preferably use a small rare earth magnet on a thread.
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showet
Cave Dweller
Member since June 2015
Posts: 65
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Post by showet on Aug 20, 2015 19:54:53 GMT -5
I had tested this earlier with a cheap magnet but got no results. At your suggestion I went out to the shop and got a better magnet, still not rare earth. I did get a response on the first rock using the stronger magnet. I will go out tomorrow and get a magnet like you recommended and check again.
Thanx.
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showet
Cave Dweller
Member since June 2015
Posts: 65
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Post by showet on Aug 21, 2015 14:58:10 GMT -5
I picked up some rare earth magnets and tested this as you suggested and yes, Rock 1 is slightly magnetic but Rock 2 is not.
I know this is not a definitive test for a meteorite, but if it is, does it hurt any value the meteorite has if I cut it?
Any reason I should NOT cut any of these?
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Post by vegasjames on Aug 21, 2015 15:43:50 GMT -5
I picked up some rare earth magnets and tested this as you suggested and yes, Rock 1 is slightly magnetic but Rock 2 is not. I know this is not a definitive test for a meteorite, but if it is, does it hurt any value the meteorite has if I cut it? Any reason I should NOT cut any of these? Cutting it would not hurt the value at all if it were a meteorite. In fact you have to cut off a piece to get it classified. DO NOT use oil to cut it though. Use clean demineralized water. Personally I would still only window it first to see what the inside looks like first. A flat lap again with clean water would be the best. |
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showet
Cave Dweller
Member since June 2015
Posts: 65
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Post by showet on Aug 21, 2015 17:35:40 GMT -5
I read that cutting a meteoroid with a diamond blade would damage or plug up the blade. I don't have a flat lap but I do have a diamond grinding wheel. Would using my diamond wheel to grind a window damage the wheel?
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Post by vegasjames on Aug 21, 2015 18:02:27 GMT -5
It is iron-nickel meteorites that will tear apart a diamond blade. If that is a meteorite it looks like it would be a stony meteorite known as a carbonaceous chondrite. These can be easily cut with a diamond saw or windowed with a diamond lap without causing any damage to either.
If it appears to be a meteorite a sample will have to be sent to a lab for analysis to get a classification. Most labs require 20 grams or 20% if less than 100 grams, which is also payment for the testing and classification. They will also want to know where it was found.
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showet
Cave Dweller
Member since June 2015
Posts: 65
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Post by showet on Aug 22, 2015 15:03:07 GMT -5
I cut a window into my Rock #1 to help determine if it is a meteorite but I don't really know what to look for, does anyone know? I have both a dry and a wet picture.   |
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Post by vegasjames on Aug 22, 2015 15:11:23 GMT -5
Definitely not a meteorite.
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showet
Cave Dweller
Member since June 2015
Posts: 65
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Post by showet on Aug 22, 2015 16:37:08 GMT -5
I now have confirmed Rock #1 is not an agate (as I originally thought before cutting) and not a meteorite, so now I have to figure out what it is!
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