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Fine Jewelry University Articles matching: “star sapphire”
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Fine Jewelry University (Show All FJU Articles)
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Gem in the Spotlight: Topaz
… difficult it is to scratch something. For reference, topaz is a bit softer than diamond which is a 10 and corundum (sapphire/ruby) which is a 9 on the scale. It is a bit harder than emerald at 7.5-8 and quartz which comes in at 7. Here are …unseen by enemies. In the Victorian era, blue topaz signified faithfulness and love. Gemology As we mentioned at the start of the article, topaz comes in a huge variety of colors. Some of these varieties have their own names: Imperial …
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The History of Diamond Cuts
…culet (the point at the bottom of the diamond). Diamonds have gone from one facet (the table) to 18 facets. This cut started to unlock the brilliance within the diamond, and variations of it are still used today. Another early diamond cut… are four triangle facets that point towards the corners of the crown. This gives the appearance of a four-pointed star. The pavilion is cut into four main facets. Moving Towards Brilliance The evolution of the diamond cuts then takes a …
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Gem in the Spotlight: Tanzanite
…, even with its rarity and dynamic look, tanzanite is still less in price than more commonly known gems like rubies, sapphires, and emeralds. Gemology of Tanzanite Gemologists refer to this gem as blue zoisite. The vast majority (current … its color. Tanzanite has a Moh’s hardness of 6-7, making it about the same hardness as quartz, softer than ruby, sapphire and emerald and hard than opal. Tanzanite has a refractive index of 1.69-1.70. History and Lore of Tanzanite Tanzanite …
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The Magic of Polarized Light
…gemstones, due to their unique chemical structure, actually polarize light themselves. These gems are doubly refractive (DR) and they will split incoming light in multiple directions. Some common examples of doubly refractive gems are sapphire, tourmaline, and moissanite. These are contrasted with singly refractive (SR) gems like diamond that only bend light in one direction. Gemologists use the term birefringence to refer to how doubly refractive a particular gem is. By …
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Gem in the Spotlight: Amethyst
… found in smaller deposits in other countries such as Russia, the United States, and Canada. Amethyst is known for its durability with a Mohs hardness rating of 7. For reference, amethyst is roughly as hard as tourmaline, softer than sapphire and topaz, and harder than opal and tanzanite. This makes it a durable gemstone that is resistant to scratching and chipping. It is also resistant to heat and chemicals which means that it can withstand daily wear and tear. Amethyst …
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Gem in the Spotlight: Emerald
… and aquamarine) and are valued for their rich green color. The intensity of an emerald’s hue depends on the presence 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 it a moderately refractive gemstone. Its specific gravity ranges from 2.65 to 2.75. One of the distinctive features of …
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Gem in the Spotlight: Opal
…a refractive index of 1.37 – 1.47 and a Mohs hardness of 5.5-6. This makes it one of the softest gemstones commonly 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 (both 2.5) to find a commonly used gem that is softer than opal. Common Opal Treatments There are several different …
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Gem in the Spotlight: Quartz
… Bloodstone Green jasper dotted with bright red spots Carnelian Reddish orange chalcedony Gemology of Quartz 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 and chemicals, which means that it can withstand daily wear and tear very well. All quartz has the same refractive index at…
