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[ileney]

A friend of mine who teaches geology to kids for the local gem and mineral club, and who is a rockhound and has been an excellent source of information in the past identified this as sodalite, but I am skeptical. He had cut up some stones for me that were larger than my tiny saw could handle. This one was purchased over 40 years ago, by my father. I've had sodalite before,but it was always opaque and never had silver color metal and what seems to be translucent yellowish/greyish quartz in it along with the streaks of opaque white quartz. This to me appears to be far more translucent than sodalite I've had before. Also, you can see the silver color metal in the wet photo (2nd photo, lower left). One slab that is only 4.5mm thick really transmits light through it, though it's still not possible to see type through it. The other slices were much thicker and the light is mostly on the borders. He did mutter something about having accidentally cut it in the wrong direction (but he'd cut many stones for me at the same time, so I didn't think anything of it). So, is this really sodalite? I haven't seen him recently so I can't ask him to look it over and ID it again for sure. If he hadn't said that, I would think it some mix of quartz maybe? Thoughts?

[rocks2dust]

Sodalite seems very possible. Not the higher quality, as some folks don't like much pyrite and/or calcite in the mix (both of which undercut). They do differ in appearance (sodalite from Afghanistan is grayer, for example), and there are several other blue minerals in the sodalite group, too (can be difficult to distinguish between them without some serious testing).

[55fossil]

   Looks like Sodalite that has not been dyed or treated like most that is on the market. Look at the sodalite cabochons sold by many reputable suppliers and they all list a host of treatments. Not sure you can cut sodalite in the wrong direction although one may more desirable.

[rocks2dust]

Not sure you can cut sodalite in the wrong direction although one may more desirable.

That had me mystified, too, since sodalite doesn't exhibit pleochroism, and a mixed rock like that wouldn't seem to have a cleavage direction. Perhaps the piece was alternating layers of sodalite, calcite, pyrite, quartz or whatever and he didn't cut it to feature more of the sodalite instead of so much pyrite, etc.

[ileney]

After looking at many images online, I am now wondering if this is Brazilian sodalite and my other material is from Namibia and if that explains the vast differences.

[lithicbeads]

I think that some of the sodalite may have some mild regional metamorphism effects. The different locals are quite different and some I saw from quartzite this year definitely looked more like dumoriterite.

[southerly]

While sold as sodalite this material is a whole mix of minerals including sodalite.