gemfeller
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Post by gemfeller on Dec 27, 2019 23:00:33 GMT -5
That's really interesting. Any ideas about where it was found? I can't ID it but would like to learn more about it.
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gemfeller
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Ring
Dec 27, 2019 22:39:00 GMT -5
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Post by gemfeller on Dec 27, 2019 22:39:00 GMT -5
Great job toiv0 . Did you do the saw work on the bezel? If so it's very neatly done. Yes, I used 18 ga sterling. A guy by the name of Jim Brandvik makes an indexing tool and holder, I had bought them a month ago and just got around to using them. I use a 2 saw blade but think I need a 3. I think he sells them on Etsy and has several u tube videos using them. Thanks for the info. I've tried to do it freehand but with very amateurish results. I think one of those tools will soon be in my bench drawer. Thanks for the tip/info.
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gemfeller
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Ring
Dec 27, 2019 20:27:48 GMT -5
toiv0 likes this
Post by gemfeller on Dec 27, 2019 20:27:48 GMT -5
Great job toiv0 . Did you do the saw work on the bezel? If so it's very neatly done.
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gemfeller
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Post by gemfeller on Dec 19, 2019 1:48:06 GMT -5
Beautiful display of gembone. I've always been curious about the geological process(es) that resulted in so many varied colors and color combinations.
Many moons ago when I worked for the University of Utah I had a front-row seat to view and study a very large dino bone assemblage. It filled several old WWII army barrack buildings on campus. There were table after table of various dino skeleton parts. One specimen in particular still stands out in memory. It was a large femur bone about 4 feet tall that had been hollowed-out over time. The cavity was filled with large facet-quality amethyst crystals similar to those found in large Brazilian geodes. I'd probably still be in jail if I'd followed my powerful urge to do a little midnight collecting.
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gemfeller
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Post by gemfeller on Dec 7, 2019 18:32:58 GMT -5
olgakniazevaru, welome to the Forum. The Mindat entry on pinolith says it's a form of dolomite limestone with inclusions of whitish magnesite. The inclusions look like pine kernels, hence the name. They call it Pinolite.
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gemfeller
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Post by gemfeller on Dec 6, 2019 23:18:39 GMT -5
First time seeing this stuff as well. That’s pretty amazing and looks great. Where is that stuff from? The classic location is Austria. But spiritstone recently posted images of fine material from British Columbia -- I think.
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gemfeller
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Post by gemfeller on Dec 6, 2019 19:16:57 GMT -5
Nice! It reminds me I have several I need to get to work on.
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gemfeller
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Post by gemfeller on Dec 6, 2019 12:45:43 GMT -5
Looks like the old Lucin "Gel" variscite. Some of that old "gel" variscite was soaked for long periods in motor oil to deepen the color. I knew a guy in Salt Lake City who specialized in doing that, selling it as "natural color." I still have a small specimen of the treated material that I watched him pull out of a tank of oil.
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gemfeller
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Post by gemfeller on Dec 5, 2019 19:50:27 GMT -5
Great cabs and interesting material. Too bad the name makes me think of an STD.
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gemfeller
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Post by gemfeller on Nov 27, 2019 13:46:33 GMT -5
This mass looks as if it has numerous gem quality crystals. There have been several large "emeralds" reported from Brazil in recent years but most have more value as curiosities than as gems. Just because a stone is beryl colored green by chromium content doesn't mean it has great value as a gem. Clarity, color and other factors determine value. This find appears to be an exceptional winner. I don't blame the owner for being ultra-careful about his identity and the stone's location. People don't play by Marquess of Queensbury rules in that part of the world.
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gemfeller
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Post by gemfeller on Nov 27, 2019 10:38:00 GMT -5
Birthday greetings Tela rockjunquie. It looks as if you already have a wonderful day planned. I hope the celebration exceeds your expectations.
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gemfeller
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Post by gemfeller on Nov 27, 2019 10:35:05 GMT -5
Happy Birthday Dave! Have a great one and many more to come.
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gemfeller
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Post by gemfeller on Nov 20, 2019 20:36:59 GMT -5
mossyrockhound, just for the record my comments weren't directed at you. They were general, just my opinion. I've faceted many stones of all sorts and I see no point in using cuts designed for brilliance on material that can't ever be brilliant. Rose cuts, on the other hand, have flat bottoms and faceted tops. My opinion is that style of cutting would be more appropriate for opaque to semi-opaque stones like agate, sugilite, gem silica, other quality chalcedonies etc. And maybe that's what the originator of this thread has in mind.
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gemfeller
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Post by gemfeller on Nov 20, 2019 14:00:09 GMT -5
Faceting of opaque or semi-opaque stones has always puzzled me. The object of faceting is to display brilliance in transparent gems, or at least that's been the traditional approach. As an opal cutter I've always wondered why faceted opals have such an appeal, especially since the discovery of Welo opal in Ethiopia. From a practical standpoint, faceting an opal results in more weight loss than cabbing. Since opals are sold by carat weight, faceting them seems counter-intuitive to me. The appeal of opals is their play of color which cabs display better, so I'm left wondering. Black diamonds? Why? There must be some mystique attached to the notion. Diamonds are prized for their whiteness, clarity and high refractive index, which results in extreme brilliance and spectral "fire." Even as a kid I was puzzled when I saw faceted black hematite being sold as "Black Alaskan Diamond." What's the appeal?
I guess I'm just out of step with popular tastes but I don't understand the logic. From a design standpoint I can understand why opaque stones might be appealing when faceted without pavilions -- basically a faceted cab -- but cutting a round "brilliant" with a pavilion in anything but transparent material just doesn't make sense to me.
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gemfeller
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Post by gemfeller on Nov 15, 2019 16:16:17 GMT -5
Excellent book. I'm glad to see it back in print. It's probably the best systematic discussion of opal properties and methods of valuation I've seen.
My only problem is that it's opal valuation system is based on a publication now known as "The Gem Guide." Subscription rates are $205 annually for the digital version, $245 for print (if I interpret their advertising correctly); and $315 for the international version.
I'm a former subscriber to "The Guide" (as named in the book) and I found its pricing astronomically high for any markets I've worked in. Those wholesale prices might apply to "prestige" operations like Tiffany & Co. but I found they had little application to the sales world I inhabit. Maybe I'm wrong - discussion is invited. I may re-subscribe to see if anything's changed.
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gemfeller
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Post by gemfeller on Nov 11, 2019 23:33:46 GMT -5
Welcome from SoCal. Nice to see you over here. I know the lady of whom you speak, and warning -- there are several like-minded opal enthusiasts here to help you keep your enthusiasm alive.
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gemfeller
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Post by gemfeller on Nov 3, 2019 13:45:38 GMT -5
Sugilite color varies a lot, from very dark purple to varying shades of magenta to lovely lilac-to-pink hues in the gel (translucent) type. The only issue in orientation I've found would be to separate gel and opaque types, which can occur in the same rough. That might also be true in pieces that mix blue richterite or pinkish-red bustamite with sugilite. These are often encountered and IMO should be cut to display the best colors. I've cut a fair amount of sugilite and the best polish (for me) has been Holy Cow! oxide on a synthetic polishing pad. It's good to know that opalpyrexia has had good results with diamond. As for Iron Out, I've never previously heard of that technique. I'll give it a try on some of my scrap pieces.
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gemfeller
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Post by gemfeller on Oct 30, 2019 22:47:09 GMT -5
I cut a lot of it. Try Zam on a muslin buff if diamond to 3K or 8K doesn't do the job for you.
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gemfeller
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Post by gemfeller on Oct 28, 2019 16:38:09 GMT -5
RickB, yes, in metamorphosed limestone turned into marble. But plain limestone is sedimentary.
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gemfeller
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Post by gemfeller on Oct 28, 2019 13:42:43 GMT -5
Tourmaline in limestone? I think not. I think R2D is right when he suggests a fossil of some sort.
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