Rocks for Cannibal Panda

Cannibal Panda (her pseudonym on Twitter) recently sent me some rocks and money to ship her a chunk of blueschist, and a few other miscellaneous items I tossed in for good measure. So here's what's going out:

One side of the blueschist block, from here, and a post on the rock and location. The lens cap is 52 mm in diameter. Also you can make the photos much, much bigger if you right click on the lens cap, then choose "Open Link in New Tab." Weird how that works.

The opposite side of the same block.

A piece of pyritized hydrothermal breccia.

And because it looked too washed out in the preview window, sitting on the lens cap for better contrast. This sample is from the stop at Mile 16.7 on this road log, in the Quartzville area.

Also on the Quartzville trip, this is vesicular basalt with zeolites. I think most of them in this sample are stilbite, but there is a little bit of natrolite, and likely some calcite as well, though I didn't look carefully enough to be certain. This is the first stop after Green Peter Dam, at Mile 0.2.

I don't think I've actually done a blog post on this location yet, except to mention it in passing. This is an utterly fabulous roadcut into what looks like it might be a rheomorphic rhyolite (it's definitely rhyolite), with lithophysae and abundant opaline and chalcedonic agate. In the center of the above photo, a single lithophysa is visible. A bit of opaline agate is visible on the lower corner. Located here, in the northwest corner of Nevada.  This sample has an excellent geopetal structure, that is, one that tells you not only the direction "up" when it formed, but gives a very precise horizontal as well. It can be found in one of the photos of the rock here, but I'm leaving it as a puzzle for Cannibal Panda to find. I don't think it'll be very obvious in the photos. No more clues for now

Since I'm a bit anal about commenting on safety issues when I post spots that I think could be hazardous I'm compelled to add: parking is NOT obvious. Park here, then walk a couple hundred yards down hill to the cut. DO NOT park in the cut. Yes, there's room, but as the road is turning inside a fairly narrow trough, you are not visible until the last second. Cars coming in the lane on the south side are coming downhill fast, and do not expect people on the side of the road. There's plenty of room to get well off the pavement on that side, where the exposure is best, and you'll hear vehicles coming, but they won't see you until literally a second or so before they pass, so they have no time to react.

Another of the same rhyolite from a different angle. (The pyritic breccia is propping the rock up to get the angle I wanted.)

And another of the rhyolite.

Another rhyolite, this one hydrothermally altered and pyritized. The glinting area to the lower right of the middle is a little cluster of pyrite.

And a vein of pyrite in the same sample. This is from Mile 14.9 in the Quartzville road log.

Another view of the vein.

And finally, a wee bit of permineralized charcoal, written up by Dana Hunter here, and from Mile 11.2 of the Quartzville Road log. This sample consists of mostly weathered surfaces. To get the sooty black to rub off on your fingers, you'll have to chip a fresh surface. But it is a cool and puzzling phenomenon: a rock soft enough to smudge your fingers, but at the same time, hard enough to scratch steel. (Incidentally, despite Dana's comments, I didn't write a whole article about it for OSU. We used one photo of a microscopic view of this rock to illustrate a GSA field guide for teachers on the petrified wood in this portion of the Western Cascades.)