Daylight fluorescent hyalite opal from Zacatecas, Mexico. This specimen fluoresces brilliantly under UV light as well as in natural daylight! The daylight fluorescence is not as intense as under a UV light, but it still brings out the beautiful green color! It's best in diffused/shaded sunlight. Measures 1 7/8" x 1 1/8" x 1 1/16" and weighs 20.17 grams. .