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Post by vegasjames on Feb 28, 2022 6:02:49 GMT -5
There seemed to be an interest in the previous post where we discussed opal synthesis, so I figured I would let people follow along with my experiments. I am not going to give out details such as specific chemicals used, but you can see the process still.
Opal is considered an amorphous (lacking crystal structure) mineraloid consisting mainly or amorphous silica and water varying from 1-20%. Opal can also contain varying amounts of aluminum oxide, which is one of the factors determining strength and stability. Water content is the other factor. Various other minor elements or molecules can also be found in opal including uranium, cinnabar, bismuth, lead, etc.
Opal starts as a concentrated silica solution. How this leads to opal formation is still debatable, but it has been proven to occur in very short periods of time. Literally as little as a year, not the millions of years normally thought to be the case. The concentrated silica solution becomes a silica gel. As the molecules start moving closer together the gel firms up and then hardens as water gets squeezed out. When the water content gets between 3-20% and in some cases as low as 1%, opal can be the result. If the water content of opal drops further the opal starts to crystalize and converts in to some form of chalcedony (common chalcedony, agate, jasper or chert/flint). Chert/flint is formed from opal derived from biogenic sources such as diatomaceous earth, which on average consists of 80% silica, 10% metal oxides including aluminum oxide and 10% moisture. Other forms of chalcedony are derived from opal produced from inorganic sources of silica such as sandstone or clay.
There are around 300 types of opal. These are separated in to two primary categories, precious and common opals. Precious opals are any type of opal with a play of color, the flash that most people associate with opal. Common opal is any form of opal that has no play of color.
Whether an opal forms as precious or common depends on silica sphere size and arrangement. If the silica spheres are sufficiently small and form in an ordered arrangement the result is precious opal. If the silica spheres are varying sizes, including excessively large, and are in a disordered arrangement the result is common opal, also known as "potch" or the very old and outdated term "opalite", which these days also refers to a synthetic opal-looking glass.
What colors the play of color shows will depend on silica sphere size. Smaller spheres form the blues and greens as where larger spheres will form the reds and yellows.
Therefore, the first goal is to form concentrated silica solutions that are then nucleated to form silica spheres of appropriate size. If all goes well then these spheres will separate by sedimentation and then reorganize themselves forming a silica gel. Over time this gel will continue to firm up squeezing out water forming opal. The resulting opal then must be slowly dehydrated preferably out of bright light to allow the opal to stabilize so it will not craze.
This is just some basics to help people follow the experiments. There is a lot more involved than this.
This first photo and video are of one of my earlier experiments. My first success with opal synthesis was done using clay kitty litter. Don't worry, it was clean litter. Later I made some other ones using different techniques since. I have not succeeded in making precious opal yet, which is my ultimate goal. This photo and video is from a gel I created maybe a year and a half ago. Unfortunately I had to transfer the gel from the original container in to a secondary jar to separate it from the other material in the jar. Therefore, it is clumpy instead of one solid piece like I would have liked. I am in the process of drying this opal gel right now by removing the lid for an hour or so every few days to allow some of the water to evaporate then, more of the water to readjust. It will be a few more months before I can remove sufficient water.
Video
This video shows a silica gel that formed with silica spheres that are too large to be any good and that formed too rapidly to allow sedimentation.
This video shows a proper silica gel for good opal formation. If you look closely you will see three layers. The bottom layer again is too large of spheres to be any good. The two upper layers were actually liquid for several days, which was great as it allowed the time I wanted for sedimentation before forming in to a very liquid gel, then in to a firm gel. I am really excited about this one. I just have to wait now to see if it develops a play of color as the silica spheres continue to reorganize themselves. I know this is still occurring as the bottom layer of larger spheres has been gradually dissolving becoming like the upper layers. Sometimes it can take several weeks to start seeing color if it is going to happen.
Here is a pic of the same gel so that the layers can be seen a little easier.
Some of the chemicals I need for these experiments are not readily available, so I have to make some of my own. Sometimes experiments go very bad. Normally the main chemical here can be stored in a plastic water bottle. Apparently the same does not apply for the mixture as I found out the hard way. Made more in glass this time and also found it forms pressure that has to be released and hardens up if not shaken frequently. I had a plastic container with some slabs in it that the chemicals also dissolved part of.
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Post by rockjunquie on Feb 28, 2022 7:55:37 GMT -5
Very cool. I didn't know you were a mad scientist.  That seems a little dangerous, but you appear to know what you're doing. Good luck! Keep us posted. |
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Post by vegasjames on Feb 28, 2022 8:47:41 GMT -5
Very cool. I didn't know you were a mad scientist.  That seems a little dangerous, but you appear to know what you're doing. Good luck! Keep us posted. My father is an inventor as was my great grandfather. So I was brought up with getting science kits, labware and lab equipment for birthdays and Christmas, and inventing in general. My dad's inventions are mainly electronics and computer stuff. Mine run a wide range from medical, fueless engines for planes, low power desalination, lots of environmental supporting stuff, diamond synthesis, etc. Always loved mixing things together to see what I could create and thinking of ways to solve problems. Some things I came up with were simply fun experiments and others functional.
There is a lot of research on opal formation out there so I have been reading a lot of studies on it to get a better grasp instead of blind experiments. So I have a real good understanding of opal formation now. Most of these experiments are just preliminary stuff to answer some questions as some of the research I have found has been contradictory. So the recent experiments are to answer some questions so I know which way I want to go with this next. Have a couple of other jars of material that are in the process of being converted. Increasing the silica solubility in them right now so I can do the next step. And still have a list of other experiments I want to try based on the research I have read. Those will be more along the lines of how opals naturally form and some of it is actually using opal silica as a starter.
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Post by rockjunquie on Feb 28, 2022 8:54:42 GMT -5
Very cool. I didn't know you were a mad scientist. That seems a little dangerous, but you appear to know what you're doing. Good luck! Keep us posted. My father is an inventor as was my great grandfather. So I was brought up with getting science kits, labware and lab equipment for birthdays and Christmas, and inventing in general. My dad's inventions are mainly electronics and computer stuff. Mine run a wide range from medical, fueless engines for planes, low power desalination, lots of environmental supporting stuff, diamond synthesis, etc. Always loved mixing things together to see what I could create and thinking of ways to solve problems. Some things I came up with were simply fun experiments and others functional.
There is a lot of research on opal formation out there so I have been reading a lot of studies on it to get a better grasp instead of blind experiments. So I have a real good understanding of opal formation now. Most of these experiments are just preliminary stuff to answer some questions as some of the research I have found has been contradictory. So the recent experiments are to answer some questions so I know which way I want to go with this next. Have a couple of other jars of material that are in the process of being converted. Increasing the silica solubility in them right now so I can do the next step. And still have a list of other experiments I want to try based on the research I have read. Those will be more along the lines of how opals naturally form and some of it is actually using opal silica as a starter.
That's awesome about your dad and grandfather. What a cool way to grow up- watching them do their things. I guess it's only natural that you should try your own things, too.
My parents weren't inventors, but I grew up with the same kinds of kits. I had a KILLER chemistry set! I never caught the inventing bug, though, for whatever reasons.
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Post by hummingbirdstones on Feb 28, 2022 9:27:44 GMT -5
This is extremely interesting, James. Being an opal nut, I will be following your experiments closely.  |
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Post by HankRocks on Feb 28, 2022 10:02:47 GMT -5
Interesting. Once I catch up on things around here(hah!!) I will see if I can find something I picked up a couple weeks ago. It an old jar of Opals that appeared to at one time been filled with water, Seen that a lot so that must be a preferred storage method? Anyway water was long gone, evaporation?, but there is a very light opalish film deposit on the inside of the jar. When I saw it I got to thinking about what you wrote and what another friend had told me.
My picture taking skills might be tested to capture the image, That and the jar is in the garage somewhere!!!
Henry
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pizzano
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Post by pizzano on Feb 28, 2022 12:08:40 GMT -5
My wife & I have a few jeweler friends who design and craft their own Cabochons, facets and other remarkable jewelry from some of the material we (my son and I) have collected, slabbed & polished over the years. They also use lab created material, sapphire, opal, emerald as well.
They seem to be very picky about their opal material, some only use resin free stones like Gilson & Galaxy.....some use both Kyoto (Kyocera) Bello & resin free depending on what metal settings they intend to incorporate............I'm under the impression you are experimenting with resin free injection, or will resin come into play at some point in the process........?
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Post by Rockoonz on Feb 28, 2022 12:34:05 GMT -5
That sounds like fun. Looking forward to seeing how this progresses.
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catskillrocks
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Post by catskillrocks on Feb 28, 2022 18:24:31 GMT -5
Glad that you've started this thread, James.
I read your other posts about man made opal
that doesn't take eons of years to form etc.
This is so cool.
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Post by vegasjames on Feb 28, 2022 18:26:28 GMT -5
Interesting. Once I catch up on things around here(hah!!) I will see if I can find something I picked up a couple weeks ago. It an old jar of Opals that appeared to at one time been filled with water, Seen that a lot so that must be a preferred storage method? Anyway water was long gone, evaporation?, but there is a very light opalish film deposit on the inside of the jar. When I saw it I got to thinking about what you wrote and what another friend had told me. My picture taking skills might be tested to capture the image, That and the jar is in the garage somewhere!!! Henry Some opals need to be stored in water if not stabilzed. This is not the same stabilization as for turquoise. Instead, if the opals have a high water content and are pulled from under the ground, if they lose too water too rapidly they will craze (crack). The higher the water content they have the more risk of crazing. Sunlight also appears to play a role so best to keep them out of sunlight, especially when stabilizing them. The most common method I have heard of for stabilization is to put the opals in a zip lock bag with a moistened paper towel then seal it up and let it sit out of the light for 6 months to several years so the opal will very slowly lose water. This allows time for the opal to stabilize itself during the slow water loss unlike rapid water loss. The higher the water content the longer it will need to be slowly dried. Might have to once in a while wet the paper towel again if the opal is being stabilized over a longer period of time.
This process does not work 100% of the time, as crazing still may occur during the process. Not sure if the aluminum oxide content will play a role in how stable the stone will be during "drying".
The reason this process can work is because the opal is technically not a solid. As I mentioned earlier, the silica spheres get attracted towards each other to form a gel, and as the spheres keep moving closer together they squeeze out water even though they are in water still. Therefore, the opal, which can actually be considered a hardened gel, actually hardens under water. And being a gel the molecules are not fixed, and thus still mobile. Same reason that when opal continues to lose water its structure changes and the opal will start to crystallize forming some type of chalcedony since the molecules and atoms are still mobile. Once the opal converts in to an ordered crystal structure of chalcedony there is no more mobility.
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Post by vegasjames on Feb 28, 2022 18:35:34 GMT -5
My wife & I have a few jeweler friends who design and craft their own Cabochons, facets and other remarkable jewelry from some of the material we (my son and I) have collected, slabbed & polished over the years. They also use lab created material, sapphire, opal, emerald as well. They seem to be very picky about their opal material, some only use resin free stones like Gilson & Galaxy.....some use both Kyoto (Kyocera) Bello & resin free depending on what metal settings they intend to incorporate............I'm under the impression you are experimenting with resin free injection, or will resin come into play at some point in the process........? No resin involved whatsoever. My ultimate goal is to make precious opal in the same manner as nature did it. These will only contain silica, water, aluminum oxide and some other trace minerals/elements just like naturally occurring opals.
I am not a fan of the current commercial synthetic opals on the market like Gilson. To me they have a weird, very unnatural look. If I recall right they call it "Lizard skin". These opals are made using a dangerous and very expensive chemical called TEOS, and their process is a lot more involved. Mimicking nature is safer, cheaper and less steps involved in the process. And there are a variety of silica sources to choose from to get more of a variety of opals such as actual opal dirt from the opal fields, sandstone, clays, diatomaceous earth, etc.
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pizzano
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Post by pizzano on Feb 28, 2022 20:27:07 GMT -5
My wife & I have a few jeweler friends who design and craft their own Cabochons, facets and other remarkable jewelry from some of the material we (my son and I) have collected, slabbed & polished over the years. They also use lab created material, sapphire, opal, emerald as well. They seem to be very picky about their opal material, some only use resin free stones like Gilson & Galaxy.....some use both Kyoto (Kyocera) Bello & resin free depending on what metal settings they intend to incorporate............I'm under the impression you are experimenting with resin free injection, or will resin come into play at some point in the process........? No resin involved whatsoever. My ultimate goal is to make precious opal in the same manner as nature did it. These will only contain silica, water, aluminum oxide and some other trace minerals/elements just like naturally occurring opals.
I am not a fan of the current commercial synthetic opals on the market like Gilson. To me they have a weird, very unnatural look. If I recall right they call it "Lizard skin". These opals are made using a dangerous and very expensive chemical called TEOS, and their process is a lot more involved. Mimicking nature is safer, cheaper and less steps involved in the process. And there are a variety of silica sources to choose from to get more of a variety of opals such as actual opal dirt from the opal fields, sandstone, clays, diatomaceous earth, etc.
That's really interesting........from what I understand, the process can take over a year to grow ready to cut........here's where two of my Wife's friends purchase their "rough" from........they craft from various size blocks and much of the "spoil" is also used integrated within other aspects of the jewelry........little is wasted......: sanwapearl.com.hk/en/about-us |
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brybry
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Post by brybry on Feb 28, 2022 20:42:15 GMT -5
I've read a couple articles on opal. One mentioned that some miners would make a pile of the opal rough and bury it under a mound of dirt to stabilize. That method would take couple of years to a decade or more depending on the water content.
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Post by vegasjames on Feb 28, 2022 21:19:17 GMT -5
No resin involved whatsoever. My ultimate goal is to make precious opal in the same manner as nature did it. These will only contain silica, water, aluminum oxide and some other trace minerals/elements just like naturally occurring opals.
I am not a fan of the current commercial synthetic opals on the market like Gilson. To me they have a weird, very unnatural look. If I recall right they call it "Lizard skin". These opals are made using a dangerous and very expensive chemical called TEOS, and their process is a lot more involved. Mimicking nature is safer, cheaper and less steps involved in the process. And there are a variety of silica sources to choose from to get more of a variety of opals such as actual opal dirt from the opal fields, sandstone, clays, diatomaceous earth, etc.
That's really interesting........from what I understand, the process can take over a year to grow ready to cut........here's where two of my Wife's friends purchase their "rough" from........they craft from various size blocks and much of the "spoil" is also used integrated within other aspects of the jewelry........little is wasted......: sanwapearl.com.hk/en/about-usYes, unlike synthesis of most stones like turquoise, diamonds, ruby, etc. this is a very slow process. The making of a saturated silica solution is pretty quick, but the gelling process is best done over a little time to allow for the sedimentation. Then the gel has to rearrange and harden, which takes a number of months. Then the water content has to be very slowly reduced over 6 months to several years. Not a project for someone who is impatient. |
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Post by vegasjames on Feb 28, 2022 21:38:37 GMT -5
I've read a couple articles on opal. One mentioned that some miners would make a pile of the opal rough and bury it under a mound of dirt to stabilize. That method would take couple of years to a decade or more depending on the water content. Yes, that would work as well as long as there is sufficient soil moisture to allow slow water loss in the opal.
I dig a lot of opal here in Nevada. The opal at the surface tends to be small pieces as it dried too fast causing it to fracture badly and break apart. If I dig down some I find much larger pieces of opal, although some can still be cracked from drying too fast. Did find a large stable boulder of opal buried at the site. It is large and stable because it is in a natural water channel that traps snow and rain and therefore the opal has been kept moister year round, but it was still close enough to the surface to allow more water loss from the stone. Was going to try and dig it out last time I was there, but it was buried under snow.
Here is an example of the surface opal. As you can see they are smaller pieces averaging the size of a quarter.
These are some pieces I dug from the ground where it had more time to stabilize. (video)
Here is my second largest piece I dug out from the ground.
I find the same with the opal I find in the drier areas such as here by Las Vegas, the pieces tend to smaller due to the drier climate so any opal found on the surface has cracked and broken in to smaller pieces.
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Post by Son Of Beach on Feb 28, 2022 21:41:13 GMT -5
This is very interesting, thank you for sharing.
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Post by vegasjames on Mar 6, 2022 22:48:27 GMT -5
Ran across this interesting video on opal synthesis. Has some great information om the play of color of precious opal. They are using TEOS in this process, which is not how I am doing this. I am trying to mimic nature, which is also why I have not tried using my centrifuges for sedimentation. Anyway, some really interesting information.
There is an ad towards the end. You can can simply scroll forward over the ad.
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That seems a little dangerous, but you appear to know what you're doing. Good luck! Keep us posted.
That seems a little dangerous, but you appear to know what you're doing. Good luck! Keep us posted.
