Mineralogical Society of America3d ago
Thin Section Thursday! Photo and caption by Chloe Morgan, UG student at James Madison Univ.: PPL picture of a chondrite meteorite showing a chondrule, a round silicate inclusion. The chondrule exhibits a barred texture due to rapid cooling. #thinsectionthursday #chondrule
Mineralogical Society of AmericaMay 21
Thin Section Thursday! contributed by Reagan Elizabeth Davis, UG student at James Madison University. The rock pictured is a Kyanite Quartzite gathered near Ogilby California. (XPL) Kyanite shows low to moderate interference colors, and bladed form. #ThinSectionThursday #kyanite
Mineralogical Society of AmericaMay 15
Image and caption from Luke Meaney, James Madison University in Harrisonburg, VA. Hornblende andesite from Mt. Shasta, CA. A near perfect Hornblende in Cross-polarized light. See the third order pinks, blues, greens, and yellows so vibrant, Picasso would approve. #thinsectionthursday #hornblende
John Faithfull 🌍πŸ‡ͺπŸ‡ΊπŸ΄σ §σ ’σ ³σ £σ ΄σ ΏπŸ§‘βœŠπŸ»βœŠπŸΏApr 26

Thanks to @History_of_Geology I know today is the birthday of Leopold von Buch, after whom the glassy rock "buchite" is named. πŸŽ‚

Mull is particularly famous for its aluminium-rich buchites, in which mullite was discovere + sapphires and other goodies. Here's a mullite buchite from an old #ThinSectionThursday - the long crystals are mullite, the clear background is glass, + together they are buchite. 🀩 More in alt txt.

FoV ca 1mm wide. #Geology #Microscopy #Mineralogy #IsleOfMull

John Faithfull 🌍πŸ‡ͺπŸ‡ΊπŸ΄σ §σ ’σ ³σ £σ ΄σ ΏπŸ§‘βœŠπŸ»βœŠπŸΏApr 23

#ThinSectionThursday A garnet monster about to gobble up a shoal of elongate sillimanite crystals.

Garnet-sillimanite quartzite from Western Australia. Field of view 2.5mm wide.

#Geology #Microscopy #Metamorphic

John Faithfull 🌍πŸ‡ͺπŸ‡ΊπŸ΄σ §σ ’σ ³σ £σ ΄σ ΏπŸ§‘βœŠπŸ»βœŠπŸΏApr 17

It may be Friday, but it's never too late for #ThinSectionThursday 😁 🀑 Here's a rock (from @geologymull) newly photo'd yesterday: a lovely fresh olivine dolerite from the very-rarely-visited Stac Mhic Mhurchaidh, an uninhabited rock west of Iona. The violet colour of the clinopyroxene crystals "bespeaks titanium" as the early C20th geological survey reports elegantly used to say. πŸ€“ 😊 Field of view about 3.5mm wide. More image info in Alt-txt.

#Geology #Mineralogy #Mull #Igneous #Microscopy

Mineralogical Society of AmericaApr 16
Thin Section Thursday! Plagioclase and pyroxene in basalt (Cross polarized light). Pyroxenes are mostly brightly colored, plagioclases are gray. Contributed by Bernhard Seubert. You can contribute too! Send image(s) and short explanation to akoziol1 at udayton dot edu. #thinsectionthursday
Bill MinarikApr 16

A garnet muscovite schist in cross-polarized light. Horizontal field of view ~ 4cm.

#ThinSectionThursday #Schist #Metamorphic #Pelite

Mineralogical Society of AmericaApr 9
Thin Section Thursday! Bornite intergrown with chalcopyrite, Reflected Light. Photo by Ingrid Kjarsgaard (c) You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Bill MinarikApr 2

Biotite replacing garnet, from the Willoughby area of the Vermont Appalachians.

#ThinSectionThursday #Vermont #Geology #Metamorphism