Search Results
Fine Jewelry University Articles matching: “Lab created sapphire”
Showing only FJU Article results. Click here to show all results.
Fine Jewelry University
-
Gem in the Spotlight: Emerald
… of chromium and vanadium in the crystal structure. Emerald’s Mohs hardness rating is 7.5-8 making it softer than sapphire and harder than amethyst and other quartz varieties. The refractive index of emerald ranges from 1.57 to 1.58, making … to make the fractures less visible. It is so common that if the stone doesn’t have a report from a reputable lab (like GIA) saying otherwise, it is assumed that it has been treated with some level of fracture filling. If you do come …
-
Gem in the Spotlight: Opal
…used in jewelry. For reference, here are the Mohs hardness values for some other gemstones you may know: Diamond 10, Sapphire 9, Amethyst 7, and Peridot 6. Turquoise is about as hard as opal, but you would need to consider Pearl or Amber (…be set into jewelry. In triplets, that thin piece of opal is sandwiched between a piece of onyx and a clear piece of laboratory grown quartz (the same material that is commonly used for watch crystals). This helps show off the opal’s …
-
Gem in the Spotlight: Quartz
… is known for its durability with a Mohs hardness rating of 7 (harder than opal and peridot but softer than topaz or sapphire). This makes it a fairly hard gemstone that is resistant to scratching and chipping. It is also resistant to heat … it to the Smithsonian’s National Museum of Natural History. It is an 8,000 pound (yes you read that correctly) slab of natural clear quartz and is one of the largest clusters ever found. Herkimer diamonds are a famous type of quartz not…
