This is a very nice Mercenaria clam specimen on gray micritic limestone matrix, with transparent golden yellow calcite crystals to over 2 cm growing from the upper hinge area. The calcite crystals fill the upper half of the specimen. This aesthetic specimen sits perfectly for display without any stand. The calcite is fluorescent blue-green under shortwave and longwave UV light (see photo), and even phosphoresces for a few seconds when the UV light is extinguished. These specimens are Plio–Pleistocene in age (1–2 million years old).