Black Druzy Quartz Round Cabochon AAA Quality Available in 8MM-12MM The active play of light of this AAAA-grade, calibrated oval black druzy quartz cabochon draws the eye; the stone is coated with titanium to bring out a consistent iridescence. Black druzy is a fit for jewelry of all types, in designs that range from simple elegance to gothic mystery. Set it in a simple pendant mounting or combine it with complementary-color stones to create more complex necklace designs and matched sets, including rings and bracelets. This stone is particuarly well suited to white metal settings. The term 'druzy' (or drusy) refers to tiny quartz crystals that are formed inside or on the surface of other stones when water containing silica particles is forced into a fissure or porous area of a rock and rapidly cools there. The clear crystals often form on top of previously deposited minerals, which give the particles their color. The crystals create a glittering effect as they reflect light from their many facets. Druzy stones are inexpensive and easy to cut into a variety of shapes?offering a great deal of color and light-play for a very affordable cost. Rio Grande's calibrated cabochons are calibrated to fit Rio Grande's corresponding size bezel cups, so you know the size you buy will fit properly every single time.