DST Seminar: Fancy Colored Diamonds: Towards an Understanding of their Color Origin
Gemological Institute of America (GIA), New York, USA
1pm - 2pm, Monday 3rd December
Materials & Analytical Sciences (MAS 2.06)
Traditionally, when people think of diamonds as a gemstone they visualize the classic colorless round brilliant. However, through the incorporation of point or extended defects in the crystal lattice, the full rainbow of colors can be found in natural diamonds. These rare diamonds, termed “Fancy Colored” in the gem trade, often command higher per carat* prices (up to $3.3 million per carat) compared to their colorless counterparts, generating great excitement at auctions and in the news. These colors can also be produced artificially through treatment of selected natural or laboratory-grown diamonds. By studying the structure, formation and destruction of color producing defects in diamond through a range of spectroscopic techniques it is possible to separate natural, treated and synthetic diamonds, maintaining transparency in the trade. In this seminar we will review some of the key color-producing defects in both natural and synthetic diamonds and see examples of how careful defect engineering can be used to produce attractive fancy colored materials.
*1 carat = 200 mg