By Indra Jhaveri
Owner of AMI Diamonds
Diamonds come in all colors of the rainbow. Most people know about white diamonds and maybe canary yellow diamonds. The colored diamonds are rarer in Mother Nature and some special colors (e.g., red, blue, green, pink, purple and orange) are very rare and considered collectibles. They are sold for record -breaking prices in auction houses. Browns (chocolate) and yellows are the more common fancy colors. According to the GIA (Gemological Institute of America), which established a universal diamond grading system accepted and practiced throughout the world, “Only one in 10,000 carat displays fancy colors and one in 25,000 carats display intense colors.” GIA grading reports of such diamonds (1.00 carat and above) with finer cuts, clarity and intensity of color have been sold for hundreds of thousands, to millions of dollars in auction houses.
So how are they created? According to GIA researcher’s theory…
Pink diamonds are caused by color centers that can selectively absorb light in the visible region of the spectrum. Color centers are the result of lattice defects or imperfections in the arrangement of atoms. The ‘Pink Star’ diamond (59.60ct) sold for $71 million at an April 4, 2017, Sotheby’s auction.
Black diamonds get their color from large quantities or minute mineral inclusions, such as graphite, pyrite, or hematite, that extend throughout the stone. A 67.05ct black diamond is well known.
Yellow diamonds are caused by the presence of nitrogen. Yellow diamonds are considered to be “fancy” when they fall outside the D to Z color range (colorless to light yellow).
Blue diamonds are caused by boron impurities presence and are very rare. Color can also be caused by radiation exposure or associated with hydrogen (enhanced and not rare). Most famous is ‘The Hope Diamond’ which at 45.52ct is a fancy, deep grayish blue and was examined by GIA in 1988.
Red diamonds are most rare and only a handful of red diamonds over 5.00 carats have been found. GIA still have not determined what causes the red color.
Green diamonds get their color when radiation displaces carbon atoms from their normal positions in the crystal structure. This can happen naturally (rare) when diamond deposits lie near radioactive rocks or artificially as a result of treatment by radiation. ‘Dresden Green’ (41.00ct) is the largest known natural green diamond.
For more information visit Indra in the store, or email [email protected]
