The International Diamond Exchange's IDEX Online Diamond Index (IDEX) and The Diamond Registry Bulletin (DR) are two sources for accurate diamond price charts, according to the Gemological Institute of America (GIA). The IDEX is published online weekly. The DR is published monthly.
The IDEX and the DR serve the diamond wholesale industry, but make diamonds available to the public at wholesale prices, according to their websites. The GIA also lists Michael Goldstein Ltd. for its quarterly publication concerning antique and colored diamond inquiries. The Michaelson Rough Diamond Pricing Guide is listed for uncut diamonds. The GIA listings are provided for informational purposes only.