2.14 ct. Mexican Daylight Fluorescent Opal
2.14 ct. Mexican Daylight Fluorescent Opal
Color: Medium Light Green-Yellow
Clarity: Eye Clean
Origin: Zacatecas, Mexico
Cut: Oval Brilliant
Treatments: None
Measurements: 10.3 x 8.3 mm
A newer and rather remarkable material. There are plenty of minerals that are fluorescent, that is to say they respond to UV light, either long or short wave. Furthermore, plenty of faceted stones have this response as well - diamonds are often quite fluorescent. But precious few, and essentially none beyond the rarified collector category, are actually daylight fluorescent. That is what you have here, this opal will glow with a yellow-green fluorescence in regular old daylight - no special light needed!
Profiled a few years ago in the Journal of Gemmology, this material is from a find of hyalite Opal in Mexico. Under completely incandescent lighting, the stone is a light stray yellow shade (photo 1). Indirect natural light even produces a moderate fluorescence response, but direct sunlight sets the stone aglow and gives you a stone with an bright yellow-green color (see photos 2 and 4). For something remarkable, use an UV light and see the response - photo 3. There are few of these truly remarkable stones in the market and very few indeed that come in at over 2 carats in weight. A rare material that will no doubt become the preeminent example of daylight fluorescence in gems.