The country has an important range of mineral resources: nickel and cobalt are found at the Mayari-Nicaro and the Moa-Baracoa regions; kaolin, quartz and marble (of high quality and assortment: red, pink, black, grey, green, white) are found on the Isle of Youth. Limestone, marl and clay for the production of cement and other construction materials can be found at Gibara, Siguaney and Santiago de Cuba. Oil and gas can be found on the northern shores of Havana and the Matanzas province. As a result of new researches, poli-metallic mineral deposits have been discovered, which are used to produce lead, zinc and baryta. Furthermore, gold, copper, magnesium, iron and chrome beds have been re-evaluated. Stocks in nickel mines ensure the production at the current processing plants allowing new investments. During the past few years quartz exploitation and it's subsequent sales have increased. Among the main timber-yielding species are Pinus caribea, mahogany tree of Cuba, cedar, red mangrove and Santa Maria tree. More than 85% of forests offer new wood and timber-yielding trees are relatively large.