Out with my wife the other day and we found something new to us.
This appears to be an opalite deposit in some old flows on the west side (Oregon)
The material grades from chalky to very solid. A very different color than I have seen.
All I collected was in the open, on the surface of an old road cut and had been for some time. A lot of it was so friable as to crumble to nothing but some was solid and held its color well. the small piece I cut took a great polish, the larger one was softer and a little more to the matte side. I was using diamond and it might come up with a different polish.
There were large areas visible above where I collected these with the spiderweb/stockwork opalite showing insitu, several feet across.
Looking forward to getting back with the right gear to put a bunch in the truck.... I think there could be some potential here.
Bill