Sphalerite
Though its best-known source was the Aliva Mine in Spain, the mineral has been sourced in a handful of other places. But it isn’t often seen in jewelry due to a few specific characteristics.
Gem NotesThe Value of Attribution
Not every provenance may be marketable. Here’s what appraisers should know about provenance and how it affects value.
The Appraiser's NotebookMandarin Garnet
Traditionally named for the pure orange hues of spessartine garnet, mandarin garnet has been increasingly scarce for more than a decade, driving prices of large and fine goods upwards.
Market TrendsTrends and Market Highlights from a Colored Stone Update in Las Vegas
GemGuide rounds up interesting insights from three industry experts.
The Trade in FocusStandard in the Making: A New Grading System for Turquoise
The Turquoise Grading System could standardize the process of evaluating the gem. It has undergone review and development and stands to bring a good addition to the trade.
Featured ArticlesGet to Know: The Cortez Cultured Pearl Farm in Mexico
The saltwater farm has restored a historic trade to the Sea of Cortez, culturing pearls in the Pteria sterna oyster in a variety of colors that never undergo any treatment.
Featured ArticlesPhotography 101
Adding light sources can go a long way in photographing gems and jewelry, but it can also create blown-out facets. To help solve that issue, the column dives into diffusing light.
Featured ArticlesMarket Uncertainty Clouds Decisions
The decline of the diamond market has slowed but continues on, while the trade struggles to understand what is required under the new G7 Russian diamond sanctions.
Diamond MarketStability for Colored Stones Continues
Expectations are favorable for colored stones in Las Vegas, while a divergent market supports growth for parts of the trade, even amid store closings.
Colored Stone Market