GeoLog

photomicrograph

Imaggeo On Monday: The Heart of a Stone

Imaggeo On Monday: The Heart of a Stone

Heart-shaped glomerocryst (aggregate of phenocrysts) made of plagioclase and pyroxene in a cordierite-bearing dacitic lava from Lipari (Eolie Islands). I study the crustal xenoliths of these lavas to understand the processes accompanying high-temperature metamorphism and crustal melting. But I came across this spectacular glomerocryst and couldn’t help but take a picture! Polarized light photomicrograph. Crossed …[Read More]

Imaggeo On Monday: Geometric Microscape of Agate

Imaggeo On Monday: Geometric Microscape of Agate

“Crazy Lace” is an agate collected in Mexico, which offers great opportunities for aesthetic photomicrography. Here we see the common arrangement of fibers of chalcedony (microcrystalline quartz) in parallel bands alternating with black thin layers of Fe oxides. Polarized light photomicrograph, crossed polarizers and red tint plate. width 5.4 mm. Sample kindly provided by Denise …[Read More]

Imaggeo On Monday: Blue Olivine in an unusual basalt

Imaggeo On Monday: Blue Olivine in an unusual basalt

Blue Olivine set in a matrix of pyroxene, magnetite and plagioclase in a basalt collected by the photographer, Bernardo Cesare, on the shore of the Sea of Galilee, Israel. Polarized light photomicrograph. Crossed polarizers and red tint plate. Width c. 2.7 mm. Who may have been throwing this stone a couple millennia ago?   Description …[Read More]

Imaggeo On Monday: Emoji from meteorites; impact spherule

Imaggeo On Monday: Emoji from meteorites; impact spherule

This is a crossed polarized light photomicrograph of an impact spherule; a small mineralisation made when a meteorite hits the Earth and melts the rock at the point of impact, from Barberton Greenstone Belt, in South Africa. These spherules are the only remnants of Early Earth’s meteorite impact history, from between of 3.2 and 3.5 …[Read More]