Description: Up for bid is a rare LW Red fluorescing Grossular Garnet. These white Grossular specimens were found near the W. L. Stifle claim near Georgetown in El Dorado County California. The find was a lens abut about 3 meters long and up to 1 meter thick which has been completely mined out. About 1,200 Grossular specimens were recovered, from thumbnail to cabinet size, but of these only about 10 to 15% were good fluorescent specimens. The best fluorescent specimens were collected along fracture zones that represent a late stage in the formation of the lens. These specimens fluoresce Red under longwave UV but have little shortwave response. Some specimens have distinct fluorescent and non-fluorescent zones. This find was reported in The Mineralogical Record, volume 50, November- December, 2019. These specimens were analyzed by XRD and it was confirmed they were pure end-member Grossular with only trace amounts of iron. It is believed that this trace amount of iron is the cause of the variability in fluorescence. Specimens with the lowest amounts of iron have good fluorescence but slightly higher amounts of iron poison the fluorescence. Colorless or white Grossular of near-end-member composition is among the rarer colors for any garnet species, and fluorescence in these is rarer still. The only other know fluorescent white Grossular is from the Jeffrey quarry in Quebec which fluoresces orange or peach under longwave ultraviolet and pink under shortwave ultraviolet light (Robbins, 1983). The fact that the Jeffery material fluoresces a different color under longwave and has a shortwave response indicates it is probably a different activator at work. There is ongoing research to determine the activator that is causing the unique fluorescence of the Georgetown Grossular. The LW fluorescence of this material is best observed with a high intensity LW LED source like a Convoy. The pictures were taken with a Way To Cool 9W LW UV source, but he picture brightness was adjusted to what you would see when using a Convoy. Description: Garnet (FL Red MW, LW best LW) Location: Stifle claims, Georgetown, El Dorado Co., CA, USA Size: 5.1" x 4.1" x 1.9" Weight: 26 oz Contact me if you have any questions. Be sure to check out my eBay store: Jim's Obscure Stuff for more fluorescent minerals and other unusual items. Domestic Shipping For domestic shipping I generally use Fed Exp Ground for heavier and more expensive items, and US Postal Service Priority Mail for lighter and less expensive items. Both services have door to door tracking and full insurance. If you have a shipping preference please let me know. If the shipping service I use costs less than eBay charges, I will refund any excess. I only charge actual shipping costs with no extra charges for packing or shipping materials and will gladly combine shipments. If the combined shipping doesnt work for some reason, I will refund any excess shipping. International Shipping I use US Postal Service Priority mail for all international shipments. Please note that due to a lack of international flights, many overseas shipments are going by boat instead of air. This can add a month or more to delivery times. Purchase at your own risk.
Price: 200 USD
Location: Woodland Hills, California
End Time: 2024-03-17T00:00:00.000Z
Shipping Cost: N/A USD
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Item Specifics
Restocking Fee: No
Return shipping will be paid by: Buyer
All returns accepted: Returns Accepted
Item must be returned within: 14 Days
Refund will be given as: Money Back
