Human heart (aortic valve) tissue displaying calcification

Density-dependent colour scanning electron micrograph of the surface of human heart (aortic valve) tissue displaying calcification in the form of spherical particles. The orange colour identifies denser material (calcified material composed of calcium phosphate), while structures that appear in green are less dense (corresponding to the organic component of the tissue). Micrographs were coloured in post-processing by combining images acquired by two modes of image acquisition that use different kinds of electron microscope detector (Secondary electron and Backscatter electron detectors). Horizontal field width is 36 microns.