English: Calla Curman memorial among the glittering cliffs at Stångehuvud nature reserve in Lysekil, Sweden. The red granite cliffs are noted for their colour and the large feldspar and mica crystals (about 10 x 10 mm) that make any part of the cliffs glitter when the sun reflects off them. The cliffs in the nature reserve were saved from quarrying at the beginning of the 20th century by Calla Curman. She bought the whole area and donated it to Royal Swedish Academy of Sciences in 1925.
This image illustrates how light, at different angles, is reflected off the feldspar crystals in the rock.