#ThinSectionThursday Here's a wonderful rock (garnet-scapolite pyroxenite, with feathery symplectite intergrowths around the garnets) from the Lewisian metamorphic complex in South Harris, in both plane polarized light, and between crosed polars. The field of view is about 2mm. See ALT text for detailed image descriptions. #Lewisian #Metamorphic #Rocks #Minerals.

Diese Farben - Those colours

#lichensubscribe #lichen #nature #naturephotography #lewisian

...and finally here's Spud on some dark metamorphosed ironstones on the west coast of Iona (also featuring at the top of the cliff a much later Permian interloper: a monchuquite dyke). The browner, massive gneisses are garnet-rich, the banded darker ones are rich in magnetite +Fe pyroxene. #Lewisian #Iona #BIF

Pink banded gneisses, showing a lot of complex faint internal structure, and a late brittle fracture displacing a dark layer. #Lewisian #Iona

More mafic banded gneiss , in contact with paler granitic gneisses, cut by a little late fracture. #Lewisian #Iona

A wee thread of lovely #Lewisian gneisses from the west coast of #Iona this morning. Dextral shear indicated by S-shaped felsic segregation in dark amphibolitic layer.

Sometimes #Lewisian foliation is good enough not to need spectacular folds.
Carnish (Càrnais) Beach, #IsleofLewis