Paul Johnson and Martha Altobelli, GIA, July 1, 2013
Recent lab examination reveals that traditional treatments such as calcium fluoride coating are still prevalent in the trade, and great care must be taken to identify them.
Read MoreChunhui Zhou, GIA, July 2, 2013
The New York lab received four baroque-shaped pearls with damaged nacre layers
Read MoreJoyce WingYan Ho and Chunhui Zhou, October 31, 2014
A rare look at natural pearls from a known Spondylus species, commonly called “thorny” oysters.
Read MoreSurjit Dillon Wong and Joyce WingYan Ho, October 17, 2013
An unusually large cultured pearl was filled with multiple cultured pearls, perhaps after the emergence of an original single-bead nucleus.
Read MoreNathan Renfro, October 17, 2013
Observing a water drop’s interaction with opal, as well as refractive index, can confirm a specimen’s hydrophane nature with less risk of breakage than total immersion.
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