quartz
Cave Dweller 
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,359
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Post by quartz on May 29, 2018 23:28:37 GMT -5
Nope, not me, simple thinker. Looks like you hit it right on with those two cuts, nice pieces. Don't discount that thin line on the black area, hummingbirdstones is right, may be a good place in there. |
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Post by 1dave on May 30, 2018 3:52:36 GMT -5
We visited the location near superior Arizona on our honeymoon in 1961. www.waymarking.com/waymarks/WMB0QD_Apache_Tears_near_Superior_ArizonaThe obsidian flowed as normal EXCEPT there was a lot of water in it. The water caused many tiny fractures in the obsidian, turning it to perlite. The "tears" have shells of perlite around them where the water got lesser and lesser, and finally not penetrating the space where the tears remain obsidian.  Totally interesting Dave, thanks for sharing. Perlite a fine high heat insulator. Industry heats perlite by the billions of tones to make it into insulation. mineralseducationcoalition.org/minerals-database/perlite/ |
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jamesp
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Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 4:05:41 GMT -5
<img src="//storage.proboards.com/forum/images/bbcode/video-preview.png" video="<iframe width="560" height="315" src=" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>" alt="Video Preview"> Speechless Robin. After playing with some of man's finest glass I must say nature is a feisty competitor for the man made. Nature has mixed it's own particles, laminates and bubbles to make a show. Reactive materials are melted into glass. This may be similar to what nature has done. This leads to a thought about laminates with man made glass and obsidian. One of the strongest bonds is a tiny drop of Super Glue between 2 sheets of flat glass pressed tightly. I should give this a go, glue thin man made to a thin slab of sheen or fire obsidian, shape to preform and then tumble polish. My Covington rock saw is quite steady and can cut guitar pick thin slabs... Maybe some obsidians can be melted in a kiln or melted with man made glass. I should do some test melts and crush some obsidian to frit and see if it will melt in with man made. |
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jamesp
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Post by jamesp on May 30, 2018 4:13:49 GMT -5
Lol, I heated a piece of obsidian to 1500F in the kiln Dave. Got a surprise. Never seen man made glass do this. Must be trapped water mentioned in your article. Before:  After  |
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jamesp
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Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 4:19:16 GMT -5
Nope, not me, simple thinker. Looks like you hit it right on with those two cuts, nice pieces. Don't discount that thin line on the black area, hummingbirdstones is right, may be a good place in there. I will saw thru the black zone and look for surprises. Glad I bought a large chunk as it makes getting the cut angles easier to line up with the bands. Yes simple thinker. Simple is genius. Complexity reduced to simplicity is the highest form of genius. Not fooling me. |
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jamesp
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Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 4:31:46 GMT -5
MsAli I took the best close up photo of a thin sliver of sheen and can not see the particles or anomalies that are causing the sheen. I suppose it would take a microscope because whatever is in there is tiny. Like a fine powdered substance. Maybe your obsidian connection folks know what is causing the sheen ? Obsidian chips are about the sharpest thing on earth, used by plastic surgeons for scalpels. 
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jamesp
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Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 7:04:15 GMT -5
Cheater wife cherry picks best glass blower scraps. Normally she composes, this time she just melted his work. Shaped on fresh nasty 60 grit wheel. The 60 grit wheel works great after it has worn a good bit. So I go haul the 70 pound buckets home. Lay it out and sort the color from the clear. Put it in small 2 gallon buckets. wash it. sort it. She just cherry picks it and makes me grind the excess glass off before she melts it. Then I have to shape on the lap and tumble it. Then she steals the finished cabs and stashes it in her vault. Life not fair. Each load from Decatur is different. This in batch picked up last week.  |
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Post by MsAli on May 30, 2018 7:57:38 GMT -5
MsAli I took the best close up photo of a thin sliver of sheen and can not see the particles or anomalies that are causing the sheen. I suppose it would take a microscope because whatever is in there is tiny. Like a fine powdered substance. Maybe your obsidian connection folks know what is causing the sheen ? Obsidian chips are about the sharpest thing on earth, used by plastic surgeons for scalpels. I would imagine it is caused from debris such as sand, crystals the gases and what ever else it picks up. Reminds me of when gas gets all swirly rainbow colored. . |
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jamesp
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Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 8:26:13 GMT -5
MsAli I took the best close up photo of a thin sliver of sheen and can not see the particles or anomalies that are causing the sheen. I suppose it would take a microscope because whatever is in there is tiny. Like a fine powdered substance. Maybe your obsidian connection folks know what is causing the sheen ? Obsidian chips are about the sharpest thing on earth, used by plastic surgeons for scalpels. I would imagine it is caused from debris such as sand, crystals the gases and what ever else it picks up. Reminds me of when gas gets all swirly rainbow colored. . Whatever is causing the reflections is very small. Silica/sand/mica ? - curious to what lurks within. Found it, here's the dope: “The various colors of obsidian are a result of several factors. Clear varieties of obsidian contain very few opaque impurities or microscopic mineral crystals. Red or brown obsidian generally results from tiny crystals or inclusions of hematite or limonite (iron oxide). Abundant, microscopic crystals of minerals like magnetite, hornblende, pyroxene, plagioclase and biotite, combined with tiny fragments of rock, likely produce the jet-black varieties of obsidian. Microscopic crystals of various types of feldspars may yield the unique blue, green, purple or bronze colors associated with rainbow obsidian. The reflectance of rainbow obsidian is likely attributed to a preferred orientation of microscopic crystals of feldspar or mica oriented along flow layers." I know that mica, silver/gold/platinum leaf, opal is sold as reflective agents in decorative glass. Maybe copper too. I should attempt to buy some tiny fire opal chips and fuse it into glass. |
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jamesp
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Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 8:38:11 GMT -5
For $19 on Ebay I will try fusing some of this opal into glass since opal does well in glass. ETHIOPIAN WELO FIRE opal  |
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Post by MsAli on May 30, 2018 9:43:30 GMT -5
For $19 on Ebay I will try fusing some of this opal into glass since opal does well in glass. ETHIOPIAN WELO FIRE opal ooohhhhh those are pretty!! |
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Post by hummingbirdstones on May 30, 2018 10:37:19 GMT -5
Speechless Robin. After playing with some of man's finest glass I must say nature is a feisty competitor for the man made. Nature has mixed it's own particles, laminates and bubbles to make a show. Reactive materials are melted into glass. This may be similar to what nature has done. This leads to a thought about laminates with man made glass and obsidian. One of the strongest bonds is a tiny drop of Super Glue between 2 sheets of flat glass pressed tightly. I should give this a go, glue thin man made to a thin slab of sheen or fire obsidian, shape to preform and then tumble polish. My Covington rock saw is quite steady and can cut guitar pick thin slabs... Maybe some obsidians can be melted in a kiln or melted with man made glass. I should do some test melts and crush some obsidian to frit and see if it will melt in with man made. The fire obsidian is probably the rarest Glass Buttes type. It is expensive and the fire lines are extremely thin. Probably not the best candidate to experiment with. I have a couple of pieces of rough that someday I will try to cut, but I'm afraid of wrecking it -- so it sits. There is an art to finding a fire layer in a piece of black obsidian with a bunch of grayish lines running through it.
I'm not even sure it's worth messing around with making "doublet" blobs with glass out of it. The impurities that will be in the natural material will probably ball up the whole works on you, plus it would be easier for you to shape obsidian cabs and throw them in your tumbler to make pendant stones if you wanted to sell them. Most of the rough obsidian is not that expensive.
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Post by hummingbirdstones on May 30, 2018 10:42:57 GMT -5
For $19 on Ebay I will try fusing some of this opal into glass since opal does well in glass. ETHIOPIAN WELO FIRE opal Must correct you here. Natural opal does not do well with high temps. It's gonna explode or fry or disintegrate or something. Opal has water in it. The opal you see in glass work is synthetic opal that is lab grown. Opal without the water. Manning International I believe was the first to create opal in a lab with their Gilson opal. Takes a whole year for the opal to grow. They closed their opal division years ago and then sold it.
Here is a link to the website for the company that owns the Gilson now:
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Post by 1dave on May 30, 2018 11:00:25 GMT -5
Sunlight on an opal can cause it to craze. Gilson created opal has no problem with heat. rockjunquie can tell you all about it. www.profoundglass.com/store/pc/viewCategories.asp?idCategory=2 Back to obsidian. varying amounts of water in layers acts like ball-bearings, creating "flow lines."  Arrowhead researchers tried to date them by the amount of breaking down, not realizing they were working with obsidian AND perlite, so they got it wrong.  |
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Post by fernwood on May 30, 2018 11:06:29 GMT -5
OMG. I would have jumped on that Opal, had I seen it. Let me know what you receive. I was thinking about suggesting you add Opal/Moonstone/Man Made Opal to your process. Imagine lips with a small portion of Opal teeth showing.
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Deleted
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Post by Deleted on May 30, 2018 11:53:56 GMT -5
The fire obsidian is probably the rarest Glass Buttes type. It is expensive and the fire lines are extremely thin. Probably not the best candidate to experiment with. I have a couple of pieces of rough that someday I will try to cut, but I'm afraid of wrecking it -- so it sits. There is an art to finding a fire layer in a piece of black obsidian with a bunch of grayish lines running through it. I'm not even sure it's worth messing around with making "doublet" blobs with glass out of it. The impurities that will be in the natural material will probably ball up the whole works on you, plus it would be easier for you to shape obsidian cabs and throw them in your tumbler to make pendant stones if you wanted to sell them. Most of the rough obsidian is not that expensive.
Agree. There are several causes to the various optical phenomena in obsidian, most all formed under high pressure conditions that will not survive in a kiln. Some Sheen types are caused by entrained gas bubbles that have been stretched into micro-fine streamers. Others also have some oriented crystals that give lens effects, and most obsidian has at least some water content (which can explode or froth up when re-heated). Fire and Fire Sheen (including some Gold Sheen) have their phenomena due to having magnetite layers stretched into nano-thin, translucent sheets that set up a thin film interference effect (TFI, the same effect that gives a thin oil slick on water its rainbow of colors, which also would very likely survive reheating. As I mentioned, obsidian forms under great pressure and heat, then cools off much more slowly than manufactured glass (which has additives that allow it to melt at lower temps and cool/anneal faster). It is not likely to be compatible to fuse alongside manufactured glass. Might be interesting to stir both obsidian and manufactured glass together, but the characteristics of the obsidian would largely be lost. I recall it being tried, along with incorporating other high-silica stones, though I don't know if anyone has documented the results. If anyone wants to experiment, I'd recommend a much slower than normal heatup and cool-down because of the trapped air and water. |
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jamesp
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Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 12:14:28 GMT -5
For $19 on Ebay I will try fusing some of this opal into glass since opal does well in glass. ETHIOPIAN WELO FIRE opal Must correct you here. Natural opal does not do well with high temps. It's gonna explode or fry or disintegrate or something. Opal has water in it. The opal you see in glass work is synthetic opal that is lab grown. Opal without the water. Manning International I believe was the first to create opal in a lab with their Gilson opal. Takes a whole year for the opal to grow. They closed their opal division years ago and then sold it. Here is a link to the website for the company that owns the Gilson now: Thanks Robin for the heads up. I may crush them to dust and see how they do as a reflective 'sheen' dust, perhaps heat the crushed particles first. Guessing they will turn into popcorn and you will say I told you so lol. Then by gosh synthetic opal from the new grower will be considered if it is not cost prohibitive. My fossilized coral is similar since it is precipitated from silica bearing limestone and lives in wet clay and my heat treating oven has indentations to show from cooking explosions. Even if I pre-heat some coral for 3 days at 200F and leave it in a dry greenhouse for a year some still bears moisture. It sounds like opal is a worser case. I will check the link out, the glass supply house carries it too. |
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 12:22:57 GMT -5
Speechless Robin. After playing with some of man's finest glass I must say nature is a feisty competitor for the man made. Nature has mixed it's own particles, laminates and bubbles to make a show. Reactive materials are melted into glass. This may be similar to what nature has done. This leads to a thought about laminates with man made glass and obsidian. One of the strongest bonds is a tiny drop of Super Glue between 2 sheets of flat glass pressed tightly. I should give this a go, glue thin man made to a thin slab of sheen or fire obsidian, shape to preform and then tumble polish. My Covington rock saw is quite steady and can cut guitar pick thin slabs... Maybe some obsidians can be melted in a kiln or melted with man made glass. I should do some test melts and crush some obsidian to frit and see if it will melt in with man made. The fire obsidian is probably the rarest Glass Buttes type. It is expensive and the fire lines are extremely thin. Probably not the best candidate to experiment with. I have a couple of pieces of rough that someday I will try to cut, but I'm afraid of wrecking it -- so it sits. There is an art to finding a fire layer in a piece of black obsidian with a bunch of grayish lines running through it. I'm not even sure it's worth messing around with making "doublet" blobs with glass out of it. The impurities that will be in the natural material will probably ball up the whole works on you, plus it would be easier for you to shape obsidian cabs and throw them in your tumbler to make pendant stones if you wanted to sell them. Most of the rough obsidian is not that expensive.
Funny you mention the obsidian cab. I am out there shaping OB cabs out of 5/16" fat slabs as you suggested. I will tumble shape the heck out of them so they have fully radius edge shape and reduce in thickness to 3/16+ if that times out properly in 60 grit SiC. And hopefully the heavy tumbling will energize the sheen material by heavy doming. Anxious to experience the sheen. Taking heed to expensive fire opal. May leave that one to the pros. Thanks for tips and warnings. |
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jamesp
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Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 12:27:18 GMT -5
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,607
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Post by jamesp on May 30, 2018 12:28:26 GMT -5
For $19 on Ebay I will try fusing some of this opal into glass since opal does well in glass. ETHIOPIAN WELO FIRE opal ooohhhhh those are pretty!! I will report back when I receive them. |
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