Boro Trivia

[e. mort]

Did you know that borosilicate occurs in nature? (Do you care. :lol: )

Dumortierite is a basic aluminum borosilicate Al6.5-7(BO3)(SiO4)3(O,OH)3.

My uncle just sent me a bit of it to polish up. Here is what it looks like so far.

Eric

[IF-Designs]

wow thats beautiful!

[Tanya]

I didn't know. How interesting. I have a small piece of it somewhere. It looks a lot like lapis.

[baylie]

Can it be used like moldivite, or gilson opal?

[Tanya]

I don't think so, although the information below indicates it's used in ceramics and porcelain. It's not actually glass, since it does form crystals. I looked it up - it's a lot harder than I thought it was. I didn't realize Tourmaline is a borosilicate! I know for a fact you can't use Tourmaline in hot glass since I've tried it with some tumbled stuff. Here's some info from my favorite mineral website, mineral.galleries.com:

Chemistry: Al6.5 - 7(BO3)(SiO4)3(O, OH)3, Aluminum Boro-silicate Hydroxide.
Class: Silicates
Subclass: Nesosilicates
Uses: As an ornamental and semi-precious stone, in the manufacture of high grade ceramics and porcelain and as mineral specimens.
Specimens
Dumortierite is a boro-silicate mineral that is used as a popular ornamental stone. It has a deep violet to blue color that is very attractive and unusual. Although it is not used as a gemstone due to a lack of clarity, it does have good hardness and a bright color. Massive dumortierite can be carved into cabochons, beads, sculptures, eggs and spheres. A variety of quartz called dumortierite quartz is massive quartz colored blue by included crystals of dumortierite. Dumortierite can be misidentified as other ornamental stones such as sodalite, lazurite and lazulite. Blue sodalite has more white portions and is much lighter in density. Lazurite and lazulite are not fibrous. In China, some dumortierite has been used as an imitation lapis lazuli in carvings.
Dumortierite is related to several other nesosilicate boro-silicates such as grandidierite, harkerite, holtite, kornerupine, magnesiodumortierite, prismatine and werdingite. Dumortierite is far more common than all of these. In fact, it is the most common boro-silicate with the exception of the more common members of the Tourmaline Group. Dumortierite is commonly found in aluminum rich metamorphic rocks in contact metamorphic regions and in some pegmatites. It can alter to the mineral pyrophyllite. Dumortierite is named for the French paleontologist, Eugene Dumortier.

[Cosmo]

Save a small piece and try encasing it.

[boroburner]

Really cool.

[Juln]

That is cool. What a pretty stone.
I wonder if some of the Chinese stone beads you see at bead stores are made form that stone? They cut plenty of Lapis and Sodalite beads.

As far as encasing... well, I guess you could try it. Just because it's borosilicate -like chemically doesn't necessarily mean it's any where near 33 coe, however.

[e. mort]

The Chinese cut a lot of beads out of this stuff, and use it as a lapis substitute.

Eric

[KristyN]

Wow, that's a pretty blue color. Mother nature does good stuff. - Kristy