Welcome to opalholicsanonymous.com where opal season lasts forever.

Article over on OA.

https://www.opalauctions.com/learn/tech ... of-an-opal

cool but it's only theory and they forget about welo which is different then LR -- there are many welo with dodgy back , sand ,clay ..etc
I don't like that and I always remove all the imperfections and my stones are perfect and free from sand and inclusions

I always struggle with that, especially when cutting LR material, which unless your dealing with a high value chunk of rough, will usually have some sandstone embedded somewhere in it.

I love watching those online tutorials like on Justin's website at Black Opals Direct where he is cutting this huge chunk of super colorful rough, like he has a whole bucket of that stuff (probably does actually, hehe) and it's all solid material, and then here I am, messing around with this piddly little thing with a couple of sparkles here and there, trying my best to extract a carat at best, hahaha.

When I first started cutting opal, I thought it was absolutely imperative that ALL sandstone be removed, and probably wasted alot of good material, live and learn, lol.

Since I've been cutting alot of boulder opals lately for my pendants, I've learned to love ironstone, and yes, even the despicable sandstone, I wonder how much all of this applies to boulders??

I should go read that, but I think I've read everything at least once over the years and gave up whining about corrections to the Virgin Valley section. Its not like I stayed in the Australian Opal Association long either. Nice idea...for Australians. Like a doublet, treated stones are concerned with what is seen, not what holds it together - just like boulder opal. Crystal opal or transparent is as facetted material and you have to be clean skin to skin or unusual as in plume garden to be considered worthy. I have a hard time getting by specimen either good looking or well shaped.

The back has nothing to so with an Opal unles it is double sided.

However, a good quality finished back shows a good cutter and thought, and professionalism.

A nice back wont add value, buit a crappy back might take a bit off.

I don't suppose he's got that video on youtube so you can embed it, does he? I can't get it to play at the link, but don't seem to have problems viewing youtube videos.

Unfortunately you can't paste any other code in the youtube link option than that of a youtube video. The code for that button specifically is designed ony for youtube.
I have seen embed button scripts for vimeo.com, but I didn't think we would need them because this is the first time I've even seen anyone post a video from that site.
If we have a real need for it, I'll look into getting a script installed for vimeo.com

The direct URL to that video works though, I think
https://vimeo.com/156327640