Post #465674 by Paipo on Tue, Jun 30, 2009 3:35 AM

On 2009-06-30 02:50, timidtiki wrote:
It's looking really good Benz . . . and should take the moko without any problems. Do you have any idea yet on what this material really is? It may be called "synthetic jade" but I cannot find any references to it on the internet. It is definitely harder than nephrite, very tough, and has a consistent grainy fracture like granite when broken . . . it is not glassy or conchoidal in fracture at all. The seller is Thialand isn't talking but he may not know. Any one else out there with ideas on this? There are some more photos of this material (including a red "synthetic jade") on Tama's Stone Carving forum.

Quoted from Ben's thread so as not to hijack it with stone discussion.

E, this may be the answer you're looking for:

Title:
Jadeite and its production
United States Patent 6908674

Abstract:
A jadeite material has a thickness in excess of about 1.0 mm and CIELAB indices of L*>42, a*+6. The grain size of the jadeite material is less than about 30 microns and is an equiaxed grain structure. The jadeite material has an optical transmission peak between 500 and 565 nm with an I/IO optical transmission ratio of over 40%. The first step in making the jadeite material is to wrap a glass block, convertible by HP/HT into jadeite and having a nominal composition of NaAlSi2O6, with a graphite or refractive metal sheet. The wrapped glass block is placed in an HP/HT apparatus, rapidly heated, and subjected therein to a pressure in excess of about 3 GPa and a temperature in excess of about 1000° C. for a time adequate to convert the glass block into jadeite. The jadeite material then is cooled and the pressure subsequently released.

HP/HT would be High Pressure/High Temperature I assume. Although I didn't carve it to the extent Ben has, it was obvious to me even with my limited experience of the stuff that it is trying to look and behave like Burmese jadeite, and it seems they've done a pretty good job (I found the above by searching for "simulated jadeite"). Interestingly, my first thought upon seeing the piece I got with it's "natural" skin was that it looked like glass, and in fact it felt that way when worked until I ground away the outer surface. I like using it too and I'll share more when I've spent more time with it....