Afghanistan is endowed with a wealth of natural resources, including extensive deposits of natural gas, petroleum, coal, marble, gold, copper, chromite, talc, barites, sulfur, lead, zinc, iron ore, salt, precious and semi-precious stones, and many rare earth elements. In 2006, a U.S. Geological Survey estimated that Afghanistan has as much as of natural gas, of oil and condensate reserves. According to a 2007 assessment, Afghanistan has significant amounts of undiscovered non-fuel mineral resources. Geologists also found indications of abundant deposits of colored stones and gemstones, including emerald, ruby, sapphire, garnet, lapis, kunzite, spinel, tourmaline and peridot.