def. Ulexite:
1. Hydrated sodium calcium borate hydroxide (formula: NaCaB5O6(OH)6•5(H2O) ), a silky, brittle, generally white evaporate mineral which often crystallizes in the form of densely-packed fibers that transmit light along the long axis of the mineral.
2. A party trick rock. Have any party guests who think that geology isn’t awesome? Just pull out your fibrous ulexite sample and say, “Hey look, I have a fiber optic rock.” Then watch the fun– the geology fun– begin.
Ulexite really does have remarkable optical properties, as the photos below demonstrate. Personally, I think that the fiber optic images produced by ulexite are even more fun and interesting than the double images caused by refraction in calcite.
I bought my ulexite sample at a rock sale. Does anyone know of good places to collect ulexite in the field?
Georneys 
I think a lot of it comes from saline basins in SE California. I’ve read that borax minerals are particularly common in areas where volcanic rocks are weathering and eroding. They do tend to be quite soluble, so if drainages go to the ocean, the element gets removed. I know borates have been extracted from a number of basin and range playas/evaporite deposits- notably Death Valley, Searls Lake, Owens Valley/Lake, and others. In Oregon’s Alvord Desert there’s an abandoned borax works; I’ve only visited it once, and didn’t think to look carefully for minerals- appeared to be mostly crust on the soil surface.
LikeLike
Ulexite mineral is find quite a lot of
in Kırka, Bigadiç and Emet in Turkey. If you visit in Turkey, you can see.
LikeLike
If you come in Turkey. I can guest you and your family.
LikeLike
Thanks, Memet! I hope to visit Turkey one day. If you have any pictures of Turkish ulexite, I would enjoy showing them here on my blog. Let me know.
LikeLike