Lapidaryforum.net
Let's Rock => Opal => Topic started by: ileney on December 12, 2016, 06:18:29 PM
-
Unusual Honduras opal - I had previously seen black basaltic Honduran opal, which is similar to dyed black Andamooka matrix opal from Australia but comes by its matrix color naturally from volcanic sources. This stuff I bought fairly recently and it is different from the usual Honduran opal in that the matrix is a light to medium gray, not black, and the crystal opal presents more like Australian Koroit or boulder opal than matrix opal- the bits of opal are larger than just pinpoints. The bottom of the crystal tends to be completely black in a super thin layer, almost like it is painted, but bringing out the color is difficult as the opal is squirrely and spins about, rather than laying in sheets or at least in an arch, like normal seam or nobbie opal. The seller only had a few pieces. Also, the crystal opal itself is weird with worm-like gold mica inclusions in places and an odd stripey look. Really it is odd. I have seen it written that the matrix is andesite.
I am not sure if I am going about cutting this properly. Here is one of the pieces uncut and a piece of the matrix with opal in process of being cabbed. I do have one piece with a slice of opal big enough that I could cut the opal out and have it stand on its own, but I am not sure if I should or if that would be an error in terms of stability or value.
Any thoughts about this or further information? I know much of the Honduras opal come from the Tablon mine but have no idea if that is where this is from.
-
Looks better than I expected seeing the thread title. My buddy who cuts rocks professionally refuses to do Honduran opals. He has tried and failed repeatedly and he saw some rough at one of the major western shows and asked a seller there how they cut them. The seller responded with "If you figure it out, be sure to let me know."
-
I have a few pieces of this type of Honduran opal. I was told it was an andesite matrix when I purchased them, and this was probably 11 or 12 years ago. I have never tried cutting them because I bought them just to have in my collection. That's all I really know about them. Saw them come out on the market back then and disappear just as fast. :dontknow:
-
Thanks. I think the person I bought this from said he got it around that time as well, then decided to sell it. Maybe he had poor luck with it as well. I have one really good stone with bright fire and am still contemplating if I should try to cut the opal out so it stands alone or if it will destabilize or lose contrast color if I do that.
-
Back then I did see some of it cut by the person who I bought my pieces from. It was cut with the matrix. The opal bits were really too small to try to cut them out of the matrix.
-
That is some nice material.....
-
After just finishing a class on opals at WH including Honduras opal, that was a phenomenal piece you have there. My instructor had several display pieces and only one was on that level of ballpark. Figure out what mine its from.
-
The only pieces of this opal have been rough. I didn't think anybody was working it. Yours looks very good. Thanks for sharing.
Steve
-
Thank you! I'll try to post some more if I finish the rest.
-
I have cut some of the black base material but I have only seen 1-2 pieces of the lighter material. With the black material, you either need to seal the material or cit around the softer spots. The best colors are in veins in the material and it requires careful sawing to get the best out of the material.
Very nice piece of a very rare opal\
Bob Johannes
The Amethyst Rose