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Monthly Archives: October 2009

Grading Pattern and Color in Opal

In our latest post to the Mardon blog, we discuss the classification/grading/description of the various play of color patterns in precious opal, focusing on the main pattern types, Pinfire, Flash, and Harlequin. Of course, a picture is worth a thousand words, so we show more than tell. Here are a few morsels, photos that we […]

How Consumers Can Get a Fair Price for Their Gold

Along with record prices for gold, we in the jewelry industry have had to contend of late with bad press about the bad gold buying practices of some in our industry– The Consumerist has run a series of articles blasting Cash4Gold, and Consumer Reports just published the results of tests they ran this last summer […]

Opals of Mexico and Australia

Don’t miss this photo gallery of $200,000 worth of opals from Mexico and Australia. ‘Nuf said!

The Last Word on Blue Sapphire

In the final installment of our series on how to evaluate the color of blue sapphires, we examine various ways to choose color, including personal preference, grading, science, and market price. The most controversial issue is whether or not the sapphire has been heat treated.  We briefly review the history of heat treatments of sapphire […]