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.
Enstatite is a rare gemstone that belongs to the pyroxene group of minerals. It is typically brown-green with a vitreous luster and is a collector's gem. Sphene. Sphene is a brilliant yellowish-green, green or brown gemstone of high luster, unique color shades and, with brilliant cut, an intense fire.adeite is found in most colors, including pure white, pink, brown, red, orange, violet, blue, black and a range of greens. Topaz. Topaz is an important gem due to its hardness and high refractive index. Topaz comes in many colors and blue topaz is especially popular.