Earthwatcher's photos with the keyword: pear

Pear leaves 'pleochroic halos'

Pear leaves 'pleochroic halos'

Earthwatcher
11 Oct 2016 262
The fungal rust spots on the pear tree leaves remind me of the pleochroic halos often seen in biotite mica crystals in thin sections of rocks prepared for petrological microscopy. www.ucl.ac.uk/%7Eucfbrxs/PLM/zircon.html