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Let's Rock => Mineral Specimens => Topic started by: John Robinson on August 26, 2017, 11:44:34 PM
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Sorry if this is the wrong board to post this question but I have two large garnets that I do not know what to do with. I thought I might just polish the facets if I was going to keep them(?)
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You could keep them as specimens, unless they are pretty clear inside they may not polish well.
If you really want to cut one, then pick the roughest and maybe do two high done cabs. Garnet can look great in cabs if it is reasonably clean.
David
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i have a large round garnet too and supports what david says. this way you a see what they look like. there is a lot of people what love garnets and large cab rings would sell very well.
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The star garnets from Idaho were broken by wrapping in a cloth and tapping lightly with a hammer. The cracks in the piece would open and leave one with fairly crack free rough. The silf that creates the eyes was concentrated in the center of the crystal so the center portion of the broken crystal would be oriented as the top of the stone. Thousands of star garnets were successfully cut in this manner.
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First thing I do is take a very bright light (LED Flashlight) and shine it through the stones from several angles. Fractures show up well this way. I have cut hundreds of Idaho Star Garnets from numerous locations including the BLM site. The rutile that makes the stars may be dense in the center, the outside or edge to edge from different locations. So there is not one test that tells all for how good the stone is. I have even cut some stones that had no translucence and gotten brilliant stars grinding from the outside. The stones from the BLM site are generally best cut from the center out.
Your top stone appears very solid but is cubic and most Idaho stones are Dodechehedron ( has a lot more faces). I would certainly try a quick polish on a corner to test color,etc. The second stone has a lot of grainy areas and layering. This may be what is considered a sand garnet or just not as high a quality. That does not mean it is not worth trying. This is the type of stone that many cutters would tap with a hammer before trying to cut. I do see some red in the photos and that is a good sign.
Use a lot of water and start with a 220 grit or finer wheel. Garnets hate heat and can even explode. good luck, neal