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Post by Mel (PrettyGritty) on Nov 20, 2023 17:52:51 GMT -5
Awhile ago I got a beautiful dulcote agate piece (not my photo but my material is nearly identical). I've never seen anything like it and only discovered what it was when I saw the Sept. 1977 issue of Lapidary Journal featuring Dulcote geodes on the cover. I tried googling but there doesn't seem to be much information about working with Dulcote material at all and the mine they came from has been closed for a long time. I ran it on the vibra lap with cerium for about 16 hours and it's got a dull shine to it but I'm wondering if it could be better. Normally I'd mess around but I only have the one piece of material. Would it maybe be worth redoing the agate on the flat lap with tin oxide? Diamond paste maybe? |
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Post by rmf on Nov 20, 2023 18:39:02 GMT -5
Dulcote Agate has calcite with the agate. I have a piece in the basement and just looked at it last week and mused whether I should slab and cab one. My guess is will only take a so so polish because of the calcite. May have to add oxalic acid to the polish to get the calcite to polish better.
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Post by Mel (PrettyGritty) on Dec 2, 2023 10:16:40 GMT -5
Dulcote Agate has calcite with the agate. I have a piece in the basement and just looked at it last week and mused whether I should slab and cab one. My guess is will only take a so so polish because of the calcite. May have to add oxalic acid to the polish to get the calcite to polish better. Thanks rmf! I was wondering how I could get it good and shiny; it’s such beautiful material with all the banding and swirls. I’ve never heard of adding oxalic acid; can you give me more details?? |
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Post by rmf on Dec 4, 2023 12:02:01 GMT -5
Dulcote Agate has calcite with the agate. I have a piece in the basement and just looked at it last week and mused whether I should slab and cab one. My guess is will only take a so so polish because of the calcite. May have to add oxalic acid to the polish to get the calcite to polish better. Thanks rmf ! I was wondering how I could get it good and shiny; it’s such beautiful material with all the banding and swirls. I’ve never heard of adding oxalic acid; can you give me more details?? I knew a guy that did marble years ago. He hand polished marble with a block of felt and tin oxide with some oxalic acid in it. I have used this on rocks with high caclium carbonate (CaCO3) content. Marble, travertine, petoskey stone etc. If you are cabbing I have had equal success with the Eastwing diamond wheel in 8000 grit from kingsleynorth.com/eastwind-diamond-fle-wheels.html#882=26748&883=26798 . I have polished with diamond Galaxy and Nova wheels down to 3000 but I had tried a discounted wheel which turned out to be eastwind and on some softer stones the 8000 grit belt on the eastwind wheel did a better job than a 8000 Nova. these would include the CaCO3 rocks and lapis
As far as SnO and Oxalic I use about 1/2# of SnO with 2 -3 tablespoons of Oxalic .
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Post by Mel (PrettyGritty) on Dec 6, 2023 8:32:21 GMT -5
Where do you get oxalic acid?
Currently I use my vibra-lap for polishing flats. I am looking for a flat spin on head for polishing on either a poly arbor or my Genie to hopefully speed up the process by using diamond paste or tin oxide though.
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Go Lick a Rock... 
