mossy-rox: I’m an igneous and metamorphic petrology kind of gal, but I when I looked down the

mossy-rox:

I’m an igneous and metamorphic petrology kind of gal, but I when I looked down the microscope at this limestone I audibly gasped. These nebula-looking things are protists called foraminifera that have been replaced by calcite. The forams are identified by their chambered tests, which are preserved in the rock, showing the protist’s original shape.