Here are several price guides, all published by independent organizations. These guides are frequently updated usually monthly, but in some instances ven weekly. The prices are based on the current or most recent market selling or asking prices - mostly from the USA.

The RAPAPORT Diamond Report is the pricing guideline that is generally the most widely used. It provides prices for all clarity grade, round brilliant cut diamonds between 0,01 and 10,99 carats, and other shape diamonds (e.g, ovals, princess cuts e.t.c.), between 0,18 and 10,99 carats. It further prices diamonds according to colour grades D to M.

Usefulness:

These price lists are quite useful to a dealer, but is of little value for the one-time buyer or the sporadic buyer, because:

• They are available on subscription only, and quite costly. Thus, would be an additional expense to budget for.
• The dealer often makes adjustments to the recommend price after examining the diamond. 

Before committing to the purchase of a diamond, prospective buyers are well advised to heed the following golden rules:

• Compare the selling prices of as many diamonds of exactly the same grades (clarity, colour and carat weight) as possible; and
• Seek independent advice whenever you are unsure.