Posted by: Rosanna Post Reply
10/21/2014, 10:43:41
I also have these nice turquoise melon beads (about 14 mm diameter), also bought over 10 years ago, and a small gather of very high polish small beads (large rectangular bead is 9 x 15 mm) that I can't place at all. One bead has a bright yellow spot which I assume is pyrite. Any info would be appreciated!
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: lopacki Post Reply
10/21/2014, 13:26:18
Rosanna,
In your first images the stone is Chinese, most likely stabilized, if not I would bet they were soaked in paraffin. I doubt they are dyed. In your image of the melon beads these might be dyed howlite, if you do a google search on howlite you can see images of it in its natural state and also dyed to look like turquoise. Again most likely Chinese made. The third group again Chinese and perhaps natural. Even if natural they have a bad habit of soaking turquoise in paraffin. Hope this helps All my best ............ Danny P.S. The best way to see if they are soaked is break a bead, most likely it will be near white on the inside. This is not high grade turquoise although it is visually very pleasing to the eye.
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Rosanna Post Reply
10/21/2014, 17:53:30
I may start smashing some beads tomorrow to see what else I can learn. I will say something right off, though - after looking at pictures of dyed howlite on line, I am pretty certain that I will never be able to tell it from real turquoise. Everything I have looks just like the dyed howlite...if I can quote Wayne, I am ready for a "pity party"!
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Sallie Post Reply
10/23/2014, 05:48:47
Turquoise question Having read all the interesting posts about turquoise, I cannot help but wonder about my turquoise items. I am posting some of my turquoise beads and hope lopacki will comment on whether they are genuine turquoise or howlite or dyed. All the items came from China land of fakes (and also of many wonderful things) The first pic shows a bird, a shell and some small animal and the reverse of these is shown in second picture. Would also be grateful if someone can tell the age and vintage of the pieces. Many thanks in advance. Sallie
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Sallie Post Reply
10/23/2014, 05:51:03
Thanks for comments.
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: lopacki Post Reply
10/23/2014, 08:21:28
Sallie,
In your first image the green item looks like glass, the other two look like howlite. They may even be plastic. My daughter bought some Chinese made skull beads that looked like turquoise and asked me to grind the backs flat for a project, as soon as they hit the grinding wheel all you could smell was plastic. Do the hot pin test on them you might find out that they are in fact plastic. The other beads in your second image are a mix most look like dyed stone a few howlite and who knows what else. I circled the one that might be turquoise in yellow and those in red I think are plastic. The only way I could give a better answer is if I had them in my hands. All my best .......... Danny
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Sallie Post Reply
10/24/2014, 07:10:46
Thank you Danny for looking and commenting. I will try needle test when I can get one. And thank you Rosanna for sacrificing your beads. What an interesting study. I too am waiting to hear the answers. Meanwhile I have one more question. Some of my turquoise beads have bubbles on them when I soak them in tap water. What is the reason and is it another sign that it has been treated ? Sallie
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Rosanna Post Reply
10/23/2014, 16:33:56
I spent a career doing mostly destructive testing... Here are five different turquoise suspects from my bead stash. In the following images you will see the insides after they were crushed with a hammer.
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Rosanna Post Reply
10/23/2014, 16:35:56
These two beads look totally different inside, but I'm not sure what that means. Danny thought the melons were dyed howlite - is this what dyed howlite looks like inside?
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: lopacki Post Reply
10/24/2014, 09:08:54
Rosanna,
I will do my best on your images. The nugget looks like low grade turquoise that has been treated with dyed resin or maybe just dyed. The melon bead leaves me clueless in regards as to what type of stone may have been used but as you can see it has been dyed and coated with some type of resin. It is not howlite because howlite is the same hardness through out and this stone is not. Looking at the round bead its obvious that the Chinese have a blue resin that they will put on most anything and if it looks like turquoise they make beads and put the resin on them. The disk bead looks like it was made with feldspar which is very common planet wide, again I would say they have dyed it. The pillow bead is either low grade treated turquoise (don't think so)or again dyed feldspar. If you take a heat source like a bic lighter and hold a piece of each stone near the edge of the flame for five or ten seconds then smell the stone more than likely you will smell plastic on every one of them. I used to work with one of the largest opal dealers out of Australia and would cringe every time he would get his nippers out to clip the edge of his rough, some of the rough being 2000 an ounce, so he could grade it. I have a pair of the nippers and use them for clipping stone of any and all types. If you can get Japanese made nippers with carbide inserts ........... Much better than a hammer and much less destructive. All my best ....... Danny
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Rosanna Post Reply
10/23/2014, 16:39:20
The round bead is brown inside (mostly) and the disk bead, a combination of blue/green and brown areas, similar to the nugget, but the brown is more intense.
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Rosanna Post Reply
10/23/2014, 16:43:34
Finally, the square pillow bead, which looks similar to the disk bead inside. I hate to impose on Danny but I think he could help everyone a lot by commenting on the inside features and what this tells us about turquoise and its look-alikes. Thanks, Dan, for the information you have already posted!
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: karavanserai Post Reply
10/24/2014, 03:23:23
martine
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: floorkasp Post Reply
10/24/2014, 04:20:41
These are beads that I know to be dyed howlite or magnesite, simply because of how cheap they were. Thought I'd follow Rosanna and smash some up. The broken one here, I think, is just like Rosanna's large nugget. Slightly lighter on the inside, but the holes are darker. It shows, I think, the beads were dyed.
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: floorkasp Post Reply
10/24/2014, 04:23:18
The first one here looks similar to Rosanna's melon bead. Much more even color, more blue tinge. The second one is more like the bigger nugget.
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Rosanna Post Reply
10/24/2014, 22:35:00
First - thank, Danny, for the detailed reply and I will definitely consider getting a pair of those nippers - they may be useful for any number of household jobs as well! I toasted a broken piece or and entire unbroken bead over a candle flame with the following results: 1. Nugget - the surface turned black at once, fair amount of smoke, and the smell was definitely burning paraffin smell. 2. Melon - this one was the most interesting. The surface was completely non- burning with no smoke, no blackening, but maybe a very slight burned plastic smell. When I looked at the burned piece under the microscope, it appears that the coating had melted and flowed into a puddle on the area away from the flame. I could scrape the puddle off in small flakes. Since this material melted but did not burn, I suspect a high temperature silicone oil. Wish I was still at work and could use the analytical lab for positive ID. The appearance of the surface that was heated in the flame changed only a little - slightly lighter blue, with some tiny white specs showing. 3. Round - the surface turned black in the flame, with smoke and a paraffin smell. 4. Disk - I had to heat an un-smashed bead since the pieces were too small to get a good result. The surface material melted into tiny droplets and had a slight plastic smell. It did not burn, so behaved like the material on the melon bead. 5. Square - blackened with paraffin odor. So in summary it appears that two different treatments (at least) were used on these beads - a flammable paraffin and a high temperature thermoplastic resin.
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: beadweyr Post Reply
10/25/2014, 06:47:08
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: beadiste Post Reply
10/25/2014, 10:12:51
The Gemmological Institute uses a hotpoint tool (which they refer to as a "destructive test," in that it of course mars the piece being investigated). I wonder if an inexpensive threadburner, easily available from Amazon, Rio Grande, Helby, EuroTool, etc etc would do the job of testing for paraffin and plastic filling? At least one wouldn't have to smash the bead or melt it with a large flame. Touching a few places around and in the holes might do the trick. Especially if one has a microscope with which to view the process, or at least a loupe to see the results. I've also found that using a stainless steel spoon to hold a few carefully carved chips over the gas burner on a stove works great to investigate aroma and melting.
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: rubyzane Post Reply
10/25/2014, 11:40:56
Except I don't want to smash any of my beads...! Thank you Danny & Rosanna for your insight on turquoise. I've started adding turquoise to my collection just these past 2 years & I realize how difficult it is to really assess what you're buying (particularly off of a computer image). Will have to read up more on this, unless Rosanna wants to keep on destroying her beads & Danny keeps on appraising!! :) Lynne
Copyright 2024
All rights reserved by Bead Collector Network and its users
Posted by: Rosanna Post Reply
10/25/2014, 20:25:00
If I want any turquoise beads in the future, I'm buying them from Danny!
Copyright 2024
All rights reserved by Bead Collector Network and its users
|