Diamond characteristics Argyle diamond mine

a large brown argyle diamond, 3.6 carats

the diamonds produced @ argyle diamond mine of average low quality. 5% of mined diamonds of gem quality, compared worldwide average of 20% (author janine roberts contends near-gem quality rating subjective , misleading because these diamonds can cut gems if desired.); of remaining 95%, evenly split between classifications of near gem quality , industrial grade; 80% of argyle diamonds brown, followed 16% yellow, 2% white, 2% grey, , less 1% pink , green. despite low production volume of pink , red diamonds, argyle mine reliable source in world, producing 90 95% of pink , red diamonds. argyle diamonds classified type 1a (see material properties of diamond), , have low levels of nitrogen impurities, colour resulting instead structural defects of crystal lattice. argyle diamonds tend fluoresce blue or dull green under ultraviolet light, , blue-white under x-ray radiation. common inclusion unconverted graphite, followed crystalline inclusions of orange garnet, pyroxene, , olivine.

annual diamond tender

each year, small collection of best pink diamonds offered in exclusive sale known argyle pink diamond tender. every 1,000,000 carats (200 kg) of rough pink diamonds produced mine, 1 carat (0.20 g) polished offered sale @ tender. invitation-only event. access collector s edition catalogue , website access in highly sought after.

in march 2009, argyle announced first ever tender of rare blue diamonds. once in blue moon collection sourced on several years, , comprised range of precious blue , violet diamonds, weighed in total 287 carats (57.4 g).

in 2016, annual argyle tender became highest selling tender in 20-year history, according diamond investment & intelligence center.