Scroll to see break-even price per barrel for oil in 2015 for select oil producers, and click on a country's name for more details. modest oil-price recovery and currency devaluations have lowered breakeven prices for countries like Russia and Nigeria, but some petrostates still need oil prices above $100 a barrel to balance their budgets.
There are dozens of types of gemstones â including diamonds, colored gemstones, and pearls â each with a unique set of physical and optical properties. GIRDLE â The narrow band around the perimeter of a polished or faceted diamond or colored gemstone.
A gemstone or gem is also called a precious or semi-precious stone, a fine gem, or jewel. It is a piece of mineral, which, in cut and polished form, is often used to make jewelry or other adornments.However certain rocks (such as lapis lazuli), or organic materials that are not minerals (such as amber or jet), are also used for jewelry and are therefore often considered to be gemstones as well.t is a piece of mineral, which, in cut and polished form, is often used to make jewelry or other adornments. However certain rocks (such as lapis lazuli), or organic materials that are not minerals (such as amber or jet), are also used for jewelry and are therefore often considered to be gemstones as well.