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Post by orrum on Sept 1, 2017 7:36:14 GMT -5
This could go in rough, slabs, or cabs section but I put it here because...well I don't know! LOL.
I can't tell lapis from sodalite in any form. I have Google it and am still lost. I get a lot of saw scrap and that sort of deals and there are blue things in them that are beautiful. I even have finished cabs that are very shiny and so dark a blue that at a glance they look black. I think they are also sodalite or lapis. If possible pics would be great.
Thanx, Bill
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Post by Drummond Island Rocks on Sept 1, 2017 8:10:13 GMT -5
All of the Lapis slabs I have ever purchased contained Pyrite in them and Sodalite wont have that.
Chuck
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Post by orrum on Sept 1, 2017 8:52:00 GMT -5
Now that's a help Chuck!!!
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Post by Bluesky78987 on Sept 1, 2017 9:09:02 GMT -5
Also sodalite tends to have more white inclusions, and often has orange inclusions too. That can be a signal. Lapis tends (not always but often) to be a more uniform color (be it dark, medium, or more denim looking).
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Post by rockjunquie on Sept 1, 2017 12:42:28 GMT -5
I'm trying to remember... doesn't the water turn white for sodalite? I know it is a beautiful blue for lapis.
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Post by coloradocliff on Sept 1, 2017 12:49:07 GMT -5
This could go in rough, slabs, or cabs section but I put it here because...well I don't know! LOL. I can't tell lapis from sodalite in any form. I have Google it and am still lost. I get a lot of saw scrap and that sort of deals and there are blue things in them that are beautiful. I even have finished cabs that are very shiny and so dark a blue that at a glance they look black. I think they are also sodalite or lapis. If possible pics would be great. Thanx, Bill
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Post by rockjunquie on Sept 1, 2017 12:58:56 GMT -5
This could go in rough, slabs, or cabs section but I put it here because...well I don't know! LOL. I can't tell lapis from sodalite in any form. I have Google it and am still lost. I get a lot of saw scrap and that sort of deals and there are blue things in them that are beautiful. I even have finished cabs that are very shiny and so dark a blue that at a glance they look black. I think they are also sodalite or lapis. If possible pics would be great. Thanx, Bill
THAT is some killer sodalite! Is that yours?
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gemfeller
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Post by gemfeller on Sept 1, 2017 13:31:45 GMT -5
It's very simple Bill. Use your nose. When you're grinding lapis the rotten egg odor is very obvious. That isn't the case with sodalite.
While not all lapis has pyrite flecks most of it does. I've never seen pyrite in sodalite so that's an easy visual tip-off.
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Post by captbob on Sept 1, 2017 13:36:25 GMT -5
sodalite ( & rose quartz ) from Brazil If sodalite has orange in it, it is most likely from Africa.
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gemfeller
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Post by gemfeller on Sept 1, 2017 13:55:12 GMT -5
That's interesting captbob . I've wondered about the source of the sodalite I cut this cab from. I *think* the supplier said Namibia but I've misplaced the invoice. It 's the first sodalite I've cut that had orange.
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Post by coloradocliff on Sept 1, 2017 14:02:51 GMT -5
THAT is some killer sodalite! Is that yours? Sodalite is in my inventory but don't care for lapis.. Too artificial looking , Too much blue. Snagged the lapis from web.
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Post by rockjunquie on Sept 1, 2017 14:04:11 GMT -5
THAT is some killer sodalite! Is that yours? Sodalite is in my inventory but don't care for lapis.. Too artificial looking , Too much blue. Snagged the lapis from web. If you ever get to cutting it and wanna sell any- let me know. That stuff is awesome!
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QuailRiver
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Post by QuailRiver on Sept 1, 2017 14:30:09 GMT -5
A streak test is the easiest way to tell the difference. Lapis will steak blue and Sodalite will streak white.
Just as a side note, becasue of it's deep blue intensity and it's color stability over time, ground Lapis pigments have been used as a paint pigment for over two millennium.
Larry C.
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gemfeller
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Post by gemfeller on Sept 1, 2017 15:12:44 GMT -5
A streak test is the easiest way to tell the difference. Lapis will steak blue and Sodalite will streak white. Just as a side note, becasue of it's deep blue intensity and it's color stability over time, ground Lapis pigments have been used as a paint pigment for over two millennium. Larry C. Yes, Leonardo da Vinci's famous Ultramarine Blue pigment was made from ground lapis. It must have been outrageously expensive at that time since the cost of transport from the source to Italy was considerable. It had been used as a paint pigment in Asia and the Middle East for hundreds of years before that time. Another side note: lapis was the original "sapphirus" or sapphire; the name was transferred to blue corundum somewhat recently because corundum color was similar and its hardness and durability are greatly superior.
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Post by orrum on Sept 1, 2017 15:30:47 GMT -5
Great tips folks, thanx! Larry that's a great tip!
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QuailRiver
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Post by QuailRiver on Sept 2, 2017 1:32:52 GMT -5
A streak test is the easiest way to tell the difference. Lapis will steak blue and Sodalite will streak white. Just as a side note, becasue of it's deep blue intensity and it's color stability over time, ground Lapis pigments have been used as a paint pigment for over two millennium. Larry C. Yes, Leonardo da Vinci's famous Ultramarine Blue pigment was made from ground lapis. It must have been outrageously expensive at that time since the cost of transport from the source to Italy was considerable. It had been used as a paint pigment in Asia and the Middle East for hundreds of years before that time. Another side note: lapis was the original "sapphirus" or sapphire; the name was transferred to blue corundum somewhat recently because corundum color was similar and its hardness and durability are greatly superior. Yes it was expensive. And Rare. Prior to the development of techniques for purifying lapis, only the highest grades of lapis, which were low in calcite and pyrite content, were useful to artists. Processes for removing calcite, pyrite and other impurities from lapis to produce the "ultramarine" pigments and their usage date back long before Leonardo da Vinci's time. There are existing European recipes for how to produce ultramarine dating to the 13th century. But many art scholars believe that ultramarine was being processed from lapis and imported into Europe even earlier. I used to use a lot of powdered pigments in antique restoration work and got interested in the history and devolvement of paint pigments and paint & varnish formulas several years ago. And did quite a bit of research on them. If anyone is interested in learning more about the topic of mineral (and other) art pigments I would recommend THE MATERIALS AND TECHNIQUES OF MEDIEVAL PAINTING by Daniel V. Thompson, THE CRAFTSMAN'S HANDBOOK "IL LIBRO DELL' ARTE" translated by Daniel V. Thompson, and THE MATERIALS OF THE ARTIST by Max Doerner. And for formulas for various mediums to mix them in FORMULAS FOR PAINTERS by Robert Massey. Larry C.
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Post by coloradocliff on Sept 2, 2017 1:55:08 GMT -5
Sodalite is in my inventory but don't care for lapis.. Too artificial looking , Too much blue. Snagged the lapis from web. If you ever get to cutting it and wanna sell any- let me know. That stuff is awesome! Will keep my eyes open. Don't remember what I pay but it might be pricey. Will look for some if you like.
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Deleted
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Post by Deleted on Sept 2, 2017 16:59:28 GMT -5
Both contain the mineral hauyne so they should both produce blue water.Lapis seems to be a blue Diopside with the carbonates being dolomite. Sodalite and Chilean lapis are hauyne. Probably a sulfur rich hauyne. As noted the real difference between sodalite and lapis is the other minerals the rock contains. Here is a link to Donald Kasper's analysis of 2 Lapis sources. donaldkasper.com/Lapis%20composition.pdfAnd the third from my backyard donaldkasper.com/Mt%20Baldy%20lapis.pdf
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gemfeller
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Post by gemfeller on Sept 3, 2017 16:10:46 GMT -5
That's really interesting info @shotgunner. I had no idea hauyne was involved in those materials. I've always wanted to get some facet-grade hauyne from Germany but so far no cigar. Finished stones are small but very beautiful.
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Post by Deleted on Sept 3, 2017 16:14:39 GMT -5
That's really interesting info @shotgunner. I had no idea hauyne was involved in those materials. I've always wanted to get some facet-grade hauyne from Germany but so far no cigar. Finished stones are small but very beautiful. And cheap! $25 for finished stones in the 3mm range. <0.1 carat For such a rare stone it seems reasonable
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