Day #76 Deskcrop: Green Slate with Pyrite Cube

Happy St. Patrick’s Day! I have something of a tradition of celebrating this holiday in rocks, so it should come as no surprise that I saved a green sample for today’s deskcrop. (It’s actually a promising sign that this is only the third of those ten deskcrops to be featured so far this year – I might actually be on pace to get all the way through this year in deskcrops and outcrops!)

Today’s deskcrop is another piece of Metawee slate, but green this time, and with a pyrite cube porphyroblast to stand in for the pot o’ gold. The pyrite is consistent with the green color of the slate in that each is indicative of reducing conditions of deposition. This cube is remarkably euhedral and lacks pressure shadows, suggesting an origin that postdates the development of the slaty cleavage in this sample. Once again, the locality of this sample is a bit fuzzy in my mind, so I’m locating it at one of the many slate quarries in the general neighborhood of it’s actual origin.

Green Slate with Pyrite Cube

Pyrite Cube Crosscutting Slaty Cleavage

Explore this and all of my 2010 Deskcrops and Outcrops in Google Earth!

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