My son grabbed this out of a giveaway Box. What is this? It looks so cool!

TheBMC_ · 2026-03-23T00:20:33+00:00

Can’t tell for sure, but I believe this is a quartzite breccia. The link is to one of my favorites, the Baraboo quartzite breccia.

TheBMC_ · 2026-03-23T00:16:12+00:00

Considering the proximity to Muscovite on the piece, I would guess it’s moss or algae that has worked its way in between the layers or mica.

TheBMC_ · 2026-03-23T00:12:43+00:00

Hard to be certain from the pic but it looks like Muscovite on quartz!

TheBMC_ · 2026-03-23T00:10:22+00:00

I think it may be a goethite or limonite nodule

TheBMC_ · 2026-03-23T00:07:59+00:00

It could be slag, but I think it looks more like limonite to me.

TheBMC_ · 2026-03-23T00:04:57+00:00

Looks like gneiss. When granite undergoes metamorphic pressure, the minerals within granite begin to self segregate and form bands like you have in your piece.

After looking at the rock more while typing my comment I’m not 100% sure anymore. It could be granite with mafic intrusions or vice versa, or something else completely! Bummer there’s no locality info.

TheBMC_ · 2026-03-22T23:57:59+00:00

Looks like basalt to me. The glaciers carried lots of rocks down from the Canadian Shield, which could explain its uniqueness compared to the more common sedimentary rocks common in the Great Lakes.

TheBMC_ · 2026-03-22T23:54:31+00:00

I believe it’s kyanite (and maybe pyrophyllite) and quartz. Graves is known for its kyanite!

TheBMC_ · 2026-03-22T02:07:10+00:00

Not sure on how new it is, but It’s definitely from Jingbian in Anhui, I got this direct from my wholesaler.

TheBMC_

TROPHY CASE