Frosterley Marble



Frosterley Marble is a black, bituminous coraliferous limestone containing fossil crinoids of the Lower Carboniferous (Mississippian ), some 325 million years ago. It outcrops in Weardale, County Durham, England, including near the village of Frosterley whence it is named.

Geology
Unlike a true marble, it is not a metamorphic rock, but is so-called because it can take a fine polish. Concentrations of such corals as Dibunophyllum bipartitum and of brachiopod remains contribute to its attractiveness when sections are polished.

Use
It is cut and polished for use as ornate stone, and was much desired for church decoration, particularly during the Middle Ages. The decorative columns found in Durham Cathedral date from about 1350. It has been used as far afield as India, as the base of the pulpit in St. Thomas Cathedral, Mumbai.