Thin Section Gallery

Thin sections are pieces of rock, sliced and ground thin and mounted on microscope slides. Each thin section in our collection was photographed in plane-polarized light (background appears white) and cross-polarized light (background appears dark blue or black), as geologists in 1900 would have viewed these under a microscope. In cross-polarized light, some minerals appear in bright hues called interference colors due to their property of birefringence.

Click on a thin section photo pair below to view it in detail.