Deleted
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Member since January 1970
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Post by Deleted on May 12, 2017 16:38:15 GMT -5
Thanks Rick!
I just learned I will need to attend shows.
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Deleted
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Member since January 1970
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Post by Deleted on May 12, 2017 22:22:04 GMT -5
I was told by a rock club member that these were Hematite. During photography, I got curious and did a couple physical tests- streak: reddish brown/brown. Hardness: >7. Habit: isometric (cubic). Color: brown/black. Lustre: submetalic? The hardness alone indicates it is NOT hematite, but that's as far as I got late last night. Educated guess' welcome! Having trouble with >7 Mohs. Maybe this needs revisiting? Perhaps with known materials. Not a test kit. Mel has a similar test kit that put an agate at >8!
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unclesoska
freely admits to licking rocks
All those jade boulders tossed in search of gold!
Member since February 2011
Posts: 934
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Post by unclesoska on May 12, 2017 23:25:20 GMT -5
I was told by a rock club member that these were Hematite. During photography, I got curious and did a couple physical tests- streak: reddish brown/brown. Hardness: >7. Habit: isometric (cubic). Color: brown/black. Lustre: submetalic? The hardness alone indicates it is NOT hematite, but that's as far as I got late last night. Educated guess' welcome! Having trouble with >7 Mohs. Maybe this needs revisiting? Perhaps with known materials. Not a test kit. Mel has a similar test kit that put an agate at >8! I have an old kit that is very inaccurate and I don't use it anymore. I also have a kit that seems right on. So in all fairness, I took a quartz crystal point and it scratched the cube. OK, so <7. Next I took a piece of amazonite, a feldspar, Moh's 6 and it also scratched it. Next a piece of glass, 5.5 Moh's also scratched the cube. I now come to the metal blade of a kitchen knife. After the bleeding stopped, I discovered the knife did not scratch the cube, even though it cut the finger. So final hardness is 5-5.5. Rockpickerforever, I owe you an apology. Looks to be limonite. I think maybe my points were a bit dull and they were skimming the cube surface.
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Deleted
Deleted Member
Member since January 1970
Posts: 0
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Post by Deleted on May 12, 2017 23:51:16 GMT -5
Having trouble with >7 Mohs. Maybe this needs revisiting? Perhaps with known materials. Not a test kit. Mel has a similar test kit that put an agate at >8! I have an old kit that is very inaccurate and I don't use it anymore. I also have a kit that seems right on. So in all fairness, I took a quartz crystal point and it scratched the cube. OK, so <7. Next I took a piece of amazonite, a feldspar, Moh's 6 and it also scratched it. Next a piece of glass, 5.5 Moh's also scratched the cube. I now come to the metal blade of a kitchen knife. After the bleeding stopped, I discovered the knife did not scratch the cube, even though it cut the finger. So final hardness is 5-5.5. Rockpickerforever, I owe you an apology. Looks to be limonite. I think maybe my points were a bit dull and they were skimming the cube surface. Awesome! You now have a new and naturally perfect test kit! Sorry about losing a digit over this. My bad.
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unclesoska
freely admits to licking rocks
All those jade boulders tossed in search of gold!
Member since February 2011
Posts: 934
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Post by unclesoska on May 13, 2017 2:35:43 GMT -5
I have an old kit that is very inaccurate and I don't use it anymore. I also have a kit that seems right on. So in all fairness, I took a quartz crystal point and it scratched the cube. OK, so <7. Next I took a piece of amazonite, a feldspar, Moh's 6 and it also scratched it. Next a piece of glass, 5.5 Moh's also scratched the cube. I now come to the metal blade of a kitchen knife. After the bleeding stopped, I discovered the knife did not scratch the cube, even though it cut the finger. So final hardness is 5-5.5. Rockpickerforever, I owe you an apology. Looks to be limonite. I think maybe my points were a bit dull and they were skimming the cube surface. Awesome! You now have a new and naturally perfect test kit! Sorry about losing a digit over this. My bad. No worries Scott, it taught me not to blindly trust my points. I'm very much a novice when it comes to mineral I.D. Thanks for pushin' the issue. You Rock!
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