minerals

Two erratics from coastal Maine

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Happy Saturday! Here are two erratics (glacially transported boulders) that I saw last week in coastal Maine. This one shows prominent subparallel striations: And this one, in the town of Penobscot, next to the greasy spoon called Bagaduce Lunch, shows aligned feldspars that suggest magmatic flow: Nothing like a good erratic to get the weekend … Read more

Quarrying soapstone

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Earlier this summer, I was lucky enough to visit a soapstone quarrying operation in Schuyler, Virginia, right on the Albemarle/Nelson County line. These soapstone bodies are metamorphosed ultramafic intrusions into the Neoproterozoic sedimentary deposits of the Lynchburg Group. The protolith peridotite sill crystallized at ~580 Ma, meaning the host sediments are older than that (but … Read more

More Messengers from the Mantle

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Since I showed off the 3D kimberlite intrusion breccias yesterday, I feel as if I owe you some other photos from that lovely exhibit at the IGC. I apologize for the poor quality of these photos – the gorgeous samples were behind glass and brightly lit, which made photography difficult. But the rocks are sooooooooo … Read more

Mineral surfaces under the SEM: 6 new micro-GigaPans

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As mentioned yesterday, my student Robin has been having some success lately in making GigaPan-scale imagery using the new desktop scanning electron microscope that our division acquired. They aren’t as super-high resolution as most of the other GigaPan images I post here, but they are very, very small – and thus expand the scope of … Read more

Five new GIGAmacro images

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Here are a few new images I’ve been working on with my home-based Magnify2 imaging system from GIGAmacro. Strophomenid brachiopods from Mississippian Mauch Chunk Formation, West Virginia: [gigapan id=”185738″] Link Boninite from New Caledonia: [gigapan id=”185707″] Link Lepidodendron scale-tree bark from Poland: [gigapan id=”185689″] Link Potassium feldspar crystal, from a pegmatite: [gigapan id=”185688″] Link Catoctin … Read more

A GIGAmacro view of the front and back of an anorthosite cobble

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Here are two views of a single anorthosite cobble, collected in the Adirondack Mountains of upstate New York: Raw, natural surface: [gigapan id=”185220″] Link Slabbed and polished surface: [gigapan id=”185217″] Link As you zoom in and explore these GIGAmacro images, see if you can find the delicate little “necklaces” (reaction rims) of garnet wrapping around … Read more