Polarized light photomicrograph of a thin section of brazilian agate.

This image is called "The Concert"
Agate is made of microcrystalline fibrous quartz, called chalcedony, and provides eye-catching photomicrographs because of the fine layering and radial textures it often displays.
I had this thin section made from a small agate slab collected at a friend’s shop. I was attracted by the unusual look for an agate: a milky white diaphanous banding and a top layer of purple amethist. A real beauty!
Under the microscope, an extremely fine-grained, unique texture came out from the milky layers of this agate, which is one of my most photogenic rocks. We can appreciate the fine grain-size in the central and top parts of the photo, as opposed to the coarser crystals in the lower band. In the latter, the parallel vertical alignment of some crystals recalls a crowd facing a stage (The Concert) or a beach.
The grain size of the chalcedony crystals – about 10 µm – makes this specimen particularly challenging in terms of focus, because light passes through an aggregate with more grains on top of each other, that create an unavoidable blurry effect.
width of view: 5,3 mm