East African Malachite. Always in shades of green, due to the presence of copper. Malachite is an attractive ornamental gemstone, often presenting striking angular striations of dark with lighter green. Siberia and East Africa are the two main commercial source areas.
Well-off pre-revolution (pre-1917) Russian residences in major cities such as Moscow and St Petersburg would often boast a drawing room coffee table top of Malachite, a 2mm thick striated polished slab, its polished surface protected with glass raised a touch off the surface with small felt tabs.