What Are Those Brown and Black Diamonds?
Short and not-so-sweet, they're poor quality diamonds served up to an unknowing public. Black because they have so much carbon inclusions in them you can't discern any crystal. Brown because they are so far down the color scale they fall off. These are the stones that were typically used for grinding up and creating industrial supplies like diamond drill bits. By the way, there's another devious stone in this group masquerading as a "gemstone," yellow diamonds. Also "junk" diamonds that are way down the color scale starting somewhere around P.
You might ask, "But what about all those news items about how valuable colored diamonds are? Great question and that's what the advertisers and marketers and store owners count on (but not the ignorant sales staff, they simply don't know any better.) The answer is the choice of words...colored diamonds versus FANCY COLORED DIAMONDS. Fancy colored diamonds exist from nature and owe their color to secondary modifying agents within their structure. Fancy is a federally protected term to protect the consumer. If a diamond is just "colored diamond" then chances are it's either been heated or irradiated or is just an off-color (bad) diamond. The black diamonds...they needed to cook in the magma a little longer.
photo: custom gent's ring with fancy yellow diamond by Tom Owczarzak of Jan David, Inc dba All Animal Jewelry