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Author Topic: How thick does a doublet have to be?  (Read 3701 times)

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vitzitziltecpatl

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Re: How thick does a doublet have to be?
« Reply #15 on: March 23, 2020, 06:48:43 PM »

Thanks for the expert info!

I've seen photos of those slicing machines, and had wondered just how thin the slices are.

bobby1

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Re: How thick does a doublet have to be?
« Reply #16 on: March 23, 2020, 07:32:14 PM »

I have opal triplets, both Spenser as well as Australian, that I made 25 to 35 years ago that have mostly cracked and some crazed over the years. I suspect the 330 epoxy drew the moisture and made them do that.
Bob
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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #17 on: March 23, 2020, 08:14:11 PM »

Hi all again,

Just to give you guys a bit more around thickness of doublets....I will try and attach some images to show that thicker is usually better when it comes to the opal content in doublets.

The pics include one of the opal slices off the slicing machine sliced at 1.2mm glued down to the obsidian (no paint or blackening agents used....ever), which I like. I will go to 1mm occasionally on smaller material. I can get a nice cabbed top at 1.2 which looks so much better in jewellery, and is way more durable...thin doublets can chip and break...similar to inlay, which is why we don’t do either! After all we all want our stones and our jewellery to last!

Another pic shows the parcel of finished doublets from the cut (one cut on the slicing machine...multi slicer).

I also included a couple of a nice larger Mintabie doublet showing how thick the opal is...50% opal content on this one..the stone is 3.3mm thick overall, tho opal is almost 1.7mm thick.

If I were cutting this for my Chinese company I cut for (boulder backed doublets), I would have had to slice this rough on the slicing machine at .7mm, and by the time it was finished the opal would be down to about .55mm....welcome to the world of mass produced inferior product!

As a commercial cutter, my business remained in high demand despite being flooded with Chinese and now Indian competition.

My secret is pretty simple. Stick to your guns with quality and excellence. Go top end, rare, hard to find rough...don’t care what it is. I am now enjoying cutting a whole lot of different (non opal) material...my cabs are never cheap, but they always sell! Be super fussy with your shaping, and try and make every piece as pleasing to the eye as you can....ignore size and carats, and always go for the best stone.

Cheers,
Mike
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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #18 on: March 23, 2020, 08:17:32 PM »

Next image opal slices at 1.2mm glued down
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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #19 on: March 23, 2020, 08:19:24 PM »

Top view of the Mintabie doublet....
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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #20 on: March 23, 2020, 08:27:42 PM »

Parcel of finished doublets..opal sliced to 1.2mm....about 1.05 when finished.
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vitzitziltecpatl

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Re: How thick does a doublet have to be?
« Reply #21 on: March 24, 2020, 06:31:26 AM »

Beauties!

But of course they are - you're a real pro. Robin and I have both been cutting opal for a while now. We both started cutting with opal instead of other stones just because that's what we liked.

Just checked a slice of Mintabie crystal here, cut by hand, and it's at 1.8 mm. I thought that was thin!

Opal Mike

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Re: How thick does a doublet have to be?
« Reply #22 on: March 24, 2020, 09:10:29 PM »

One of my better doublets...really thick absolute gem crystal rough allowed me to get a nice high cab on it, and still look incredibly dark and bright.

The opal content in this doublet is more than most natural Lightning ridge blacks which in my opinion are more often than not just natural doublets.

The difference is, if this were a solid it would be a 14 to 16k stone. As a doublet we hand crafted an 18k gold hand made bezel set ring with some chenier set diamonds and sell it for around $1200 US.

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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #23 on: March 24, 2020, 09:13:33 PM »

Not sure what happened getting that pic from my phone to my iPad to you guys, but it is actually a fairly round oval around 11x 9.5 from memory. I will upload another one and see what happens.
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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #24 on: March 24, 2020, 09:14:59 PM »

That last green pair looks right...try this one again.
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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #25 on: March 24, 2020, 09:19:06 PM »

Lucky I am bored lol...locked down here staying safe in South Oz.

Hope you like these doublets. We have been doing this forever...opal business..I absolutely love cutting doublets...
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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #26 on: March 24, 2020, 09:28:15 PM »

That last green orange pair ( we say that because crystal opal faces blue or blue green unless it has some orange / red in the side face. When this occurs we get nice vibrant ‘pattern’ green on the top face.

I will slice a lot of green orange rough on the side if it is thick enough...to get the better face, especially blue green material.

This last one is just a beautiful stone. Super thick opal..almost half opal half obsidian...lovely cabbed top.

This is my favourite type of opal...again green orange crystal, this one is old Lambina material. Fabulous deep chaff pattern.
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vitzitziltecpatl

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Re: How thick does a doublet have to be?
« Reply #27 on: March 25, 2020, 08:18:15 AM »

Wow.

We're lucky you're bored. I collected finished goods for a long time before I started cutting, and your doublets are as good as any I've ever seen in top-end shops anywhere.

Good of you to bring up the point on pricing, too. Many people don't understand that aspect of opal cutting.

ileney

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Re: How thick does a doublet have to be?
« Reply #28 on: March 25, 2020, 08:37:50 AM »

My gosh, these are amazing! Simply gorgeous! Thank you so very much for posting all this information.

I don't have a slicer, so I am cutting on a saw and grinding down as far as I need to get the color I want (mostly nowhere near as good as these, that's for sure!)
I do have thick enough material to do solid Coober Pedy's so mostly I'm using off cuts from solids, thin ground pieces I got out of highly included rough, or those rare pieces that are too thin to start with for doublets/triplets, but most of those are pretty tiny.
I see you have won your skill through years of hard fought experience. I'm a hobbyist but having fun with it. Most of my rough isn't of this quality and I'm unclear where to find this kind of rough, but then I'm learning now so I don't want to spend a fortune on my rough at this point. However, your post made me realize that I do at least have enough thickness of opal in the stones I've made.  I was going to post mine when they are all done (I have many small ones in process but had to move everything due to COVID and haven't found the glues yet.) I may post them as an example of being more like what a beginner can expect!
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Opal Mike

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Re: How thick does a doublet have to be?
« Reply #29 on: March 25, 2020, 04:05:50 PM »

I cut a lot of doublets without the slicing machine. I have 6 ounces of small thin mostly red crystal that I will have to hand lap and glue down...none of this will go on the slicing machine. This material, I flatten one side on the lap to get to clean opal...and will often glue down without touching the top too much...if I can see where the sand etc is. ( hold piece up to the edge of a lamp and see how deep any sand is...

Also, I cut an awful lot of more ‘commercial’ doublets in between every really good one. I like them all! There is no bad opal lol...

With this virus and the halt I am predicting to our sales, I am going to be spending more time back in my workshop health permitting.. ( my health is a bit of an issue)

I will be putting a couple of doublet cuts through the slicing machine...one nice crystal cut for some bigger doublets, and another large cut of pretty nice grey (milky) material...that others don’t consider for doublets.

I will post some pics of the opal and the different stages so you can see that lots of Coober Pedy rough can make really nice doublets.

The milkier ones are not nearly as dark, or dramatic in terms of colour, but I really like them! They have lovely softer colours and great patterns and look beautiful...

Jenni and I have always liked nice white based opal.

This material has traditionally been a lot cheaper than the crystal, largely because there was always a lot of it coming out of the ground... not any more!

I know opal is now really hard to buy in the rough, and is super expensive compared to a lot of other gem rough.

There is currently a lot of Ethiopian opal on the market, but nearly all this material is too jelly like to cut doublets, and a bit dodgy for solids unless you get lucky.

I know a guy from Coober Pedy who mines and cuts a lot of doublets and makes simple jewellery he sells on Etsy and eBay etc. Speaking to him yesterday, he will have several parcels of rough for sale over the next couple of weeks.

Business is likely to get pretty tough I think...I will speak to him again and ask him if he can break down his parcels into smaller amounts to give guys like you a chance to have a play with some better material.

I will let you know, or if any of you want to buy a bigger amount, you can find him on Etsy under WorldClassOpals...

His name is Lochy and he is a good guy...I have known him and his family since he was a young boy, and he is very honest. He cuts all his doublets by hand by the way (no slicing machine), although he has made a jig up to attach to his trim saw so he can wax a larger stone to a block and slice it on the trim saw one slice at a time...He also uses Ironstone for his backing which I am not keen on as you know, but it works for him...which you will see if you find his jewellery.

I will leave you with a pic of something a bit different.. Australian Pink Opal... pretty cheap material.. get on it and have some fun..contact Glenn Archer Australian Outback Mining....for those that don’t know him....enjoy! He is a real gem!!

Cheers,
Mike
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