Human heart (mitral valve) tissue displaying calcification

Density-dependent colour scanning electron micrograph of the surface of human heart (mitral valve) tissue displaying calcification in the form of spherical particles. The blue colour identifies denser material (calcified material composed of calcium phosphate), while structures that appear in green and red are less dense (corresponding to the organic component of the tissue). Micrographs were coloured in post-processing by combining images acquired by three modes of image acquisition that use different kinds of electron microscope detector (Secondary electron and Backscatter electron detectors). Horizontal field width is 16 microns.