RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 19, 2014 21:08:15 GMT -5
I just checked Wikipedia and found this:
"In 1912, the first deposit of distinct, single-crystal turquoise was discovered in Lynch Station, Campbell County, Virginia. The crystals, forming a druse over the mother rock, are very small; 1 mm (0.04 in) is considered large. Until the 1980s Virginia was widely thought to be the only source of distinct crystals; there are now at least 27 other localities.[7]"
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 19, 2014 21:02:33 GMT -5
I have a few with some kind of crystals? stinkn out of a couple. Would that be turq? Interesting thread. Besides one mine in Virginia (of all places), turquoise doesn't form as crystals. It's almost always a cryptocrytalline mineral. The turquoise crystals from Virginia are too small to cut.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 18, 2014 22:42:13 GMT -5
The other stone that many dealers misrepresent is the "Seafoam Jasper". It should be obvious that this stuff is dyed and probably reconstituted. There are simply too many different colors and varities available - i.e a red, a blue, a green, a purple, etc. and this should be the first tip off. True red or purple stones (without any masking) might be the least common colors in natural stones. Even when you pick-up a piece of "seafoam whatever" it doesn't have the same weight as a jasper. The first time I saw the "purple turquoise" was about four or five years ago. I thought it was manufactured more recently than 20 years ago but don't know for sure. Do a little searching and you'll find they're selling just about every color of "turquoise" imaginable. Consumers gobble it up hungrily while passing over the real thing. Human nature's gullible and the marketers figured out how to exploit it long, long ago. The scam that really pi$$es me off is "Crab Fire Agate." It's all phony ceramic junk but it apparently sells like hotcakes. www.google.com/search?q=crab+fire+agate&biw=1536&bih=674&tbm=isch&tbo=u&source=univ&sa=X&ei=GaAbVJ6cOsOUyATmv4KQBQ&sqi=2&ved=0CE4QsAQI see plenty of the colored turquoise at the gem shows (Only 18 this year or 111+ since 2008.). So no searching necessary. Fortunately I still sell plenty of real turquoise to jewelers who want the genuine stuff.....
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 18, 2014 21:20:47 GMT -5
The other stone that many dealers misrepresent is the "Seafoam Jasper". It should be obvious that this stuff is dyed and probably reconstituted. There are simply too many different colors and varities available - i.e a red, a blue, a green, a purple, etc. and this should be the first tip off. True red or purple stones (without any masking) might be the least common colors in natural stones. Even when you pick-up a piece of "seafoam whatever" it doesn't have the same weight as a jasper.
The first time I saw the "purple turquoise" was about four or five years ago. I thought it was manufactured more recently than 20 years ago but don't know for sure.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 18, 2014 15:53:46 GMT -5
"Green" amethyst "White" turquoise "Blue" Morganite Heck, even Tanzanite is a marketing name for heated brown zoisite and the public soaks it up. The purple portion of "purple" turquiose is just harder turquoise that won't accept the dye is what I've been told. The purple portion is the softer turquoise chalk that will take coloring. The blue bits are usually already stabilized blue turquoise that won't change color because it's already stabilized or rarely, harder turquoise that won't accept dying. The gold color is bronze tinted epoxy resin that they use to fill in the larger cracks and etc when they compress it all into a block. Then they let the resin "cure" and finally put the molds in an oven to finish curing and setting the resin. There is NO natural purple colored turquoise anywhere in the world. Nor lime green, orange, florescent yellow, etc etc etc. In complete agreement about the colors of turquoise. Just did't know that some parts of the uncolored part of this product was stabilized prior to dying the remainder. As originally mentioned, "purple" turquoise is only a marketing name.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 18, 2014 9:29:18 GMT -5
"Green" amethyst "White" turquoise "Blue" Morganite
Heck, even Tanzanite is a marketing name for heated brown zoisite and the public soaks it up.
The purple portion of "purple" turquiose is just harder turquoise that won't accept the dye is what I've been told.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 16, 2014 21:07:12 GMT -5
Nice poster! See you there.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 10, 2014 21:04:01 GMT -5
It would have been much simpler if DOF was originally named depth of focus.....
No one has mentioned that DOF is also directly related to the film format (say 35mm vs. 8x10) or the size of the sensor for digital. With the same aperture, a DSLR will always produce less DOF than a point and shoot camera with a smaller sensor with all other factors being identical. The same results (I.e. less DOF) occurs when using a telephoto lens vs. a wide angle lens.
Results may also appear different based on the metering mode of the camera -spot, center weighted or full frame average. Since digital "film" is so cheap, its always a good idea to experiment with every control and read through the instruction/destruction manual.
A lot of cameras have a DOF preview button -almost always on the lower left of the lens mount-that can be helpful in determing the correct DOF.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 9, 2014 21:36:44 GMT -5
I just spent the entire walking through the Denver show.Saw lots and lots of jewelry. Yet the nicest piece I have seen today is this one. Three thumbs up for Donnie!!!
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 6, 2014 21:11:42 GMT -5
Here's the info on resurfacing wheels that Orrum was referring to. linkWelcome to a great hobby and the forum!!
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Aug 16, 2014 7:56:09 GMT -5
The V5 is a top of the line faceting machine and should be a real joy for cutting. Before making the commitment to lessons, check which brand of machine you will be learning on. There are some differences between brands and it helps tremendously to learn on the same type of machine you have. Also, weigh the cost vs. benefits of a group lesson vs. one-on-one instruction. Personally I would go for the individual lessons and hope to develope a long term relationship with an experienced facetor. They are often very excited to share their knowledge and have someone to mentor.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Aug 15, 2014 17:36:55 GMT -5
As long as it's feasible, go with what the customer wants. Everyone doesn't have the same sense of design. Throw in the differences between men and women, then add the different tastes between generations, mix a few other factors into the equation and hope the guy is starting a trend that is profitable for you!
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Jul 30, 2014 21:47:46 GMT -5
The QIA office is closed from sometime in the spring until fall. Check their website. I don't remember the specific dates. The last few years, there have been extra vendor spaces right up to the show. Of course you have a better selection/location earlier. Save yourself time and get your Quartzsite business license at city hall before checking in at the QIA office. It's always something of a circus.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Jan 6, 2014 21:00:31 GMT -5
Yes, I've seen this before. It's astrophyllite. Often confused for rutile.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 12, 2013 20:54:13 GMT -5
I'm viewing this from my phone. So if the right edge is concave I'll take your word for it. It just looks straight on this device while the banding certainly enhances the convex shape of the opposite side.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 12, 2013 20:29:56 GMT -5
I love the way the bands of color repeat themselves while starting at the bottom right and then working upward. This is truly a designer cab.
I was kind of hoping someone else would mention this - the curve is actually convex and not concave. (For concave remember "cave" or down.)
Either way, nice grinding and polishing!
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Sept 5, 2013 9:45:10 GMT -5
While not a red mineral, Brochantite came to mind for some reason. I may have seen it listed as being found in Sonoran Sunrise. A little trivia. Jimmy and Joyce Vacek at 49er Minerals link are widely credited with naming this material. The morning after collecting the first batch from the Mexican miners, they were leaving the village and were greeted by a super colorful sunrise. Whether it's called Sonoran Sunrise or Sonora Sunset or any of the other variations is just splitting hairs. There's even a vendor at the rock shows now selling a manmade version! He'll be at the Miner's Co-op in Denver next week. This is certainly a really nice cab and I suspect isn't the usual cuprite version of Sonoran/Sonora Sunrise/Sunset.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Aug 29, 2013 7:51:47 GMT -5
Too bad we don't have any dino bone like this linkPut it on a knife with Damascus steel....
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Mar 8, 2013 22:05:15 GMT -5
After re-eading the section on temperature on the Silica Polymorph page from quartzpage.de it does state opal may morph to quartz - with sufficient time. I stand corrected.
It does seem odd that while opal is loosing water molecules, the specific gravity increases. Its also odd that while opal would display a break down of the molecular structure through crazing, the hardness actaully increases as quartz.
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RocknCritter
spending too much on rocks
Member since November 2008
Posts: 489
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Post by RocknCritter on Mar 8, 2013 10:07:17 GMT -5
As a trained geologist, I completely understand your point about the structure. The point I make about opal just becoming quartz is.. The chemical formula of opal is Si02.nH2O, of quartz is Si02 and the difference is .nH2O. Opal is not listed as a polymorph of quartz as it does not share the same chemical formula - they are different. Dried opal Si02.nH2O becomes Si02 - quartz Here is some documentation to clear-up the confusion. From www.quartzpage.de/gen_mod.htmlSiO2 Polymorphs Silica Polymorphs (Network Silicates) Quartz, Low-Quartz, α-Quartz, Alpha-Quartz High Quartz, β-Quartz, Beta-Quartz α-Tridymite, Low-Tridymite
β-Tridymite, High-Tridymite
α-Cristobalite, Low-Cristobalite
β-Cristobalite, High-CristobaliteMoganite (Lutecite, Lutecine) Coesite Keatite Non-Silica Polymorphs Stishovite Seifertite Non-Crystalline Mineraloids Opal (contains water), with 2 microcrystalline and 2 non-crystalline variantsLechatelierite, Silica Glass From www.mindat.org/min-3004.htmlAlthough it is still (2007) regarded as a valid mineral species for historical reasons, Opal is not a true mineral in the accepted sense of the word as it is either composed of Cristobalite and/or Tridymite or composed of amorphous silica. Opal is broken down into four types: Opal-CT Cristobalite-Tridymite Opal-C CristobaliteOpal-AG Amorphous -Gel (closely packed amorphous silica spheres form a diffraction grating to create Precious Opal). Opal-AN Amorphous-Network (Hyalite) If de-hydrated opal morphed into quartz, then re-hydrated quartz would become opal. Neither of these scenarios is feasible. If soaking quartz (silica) in water turned it into opal, imagine what all the beaches in the world would be like A change in the chemistry doesn't alter the mineral structure. Think about pseudomorphs...............
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