Because polished gems with high lusters usually have high refractive indices, and polished gems with low lusters typically, but not always, have lower refractive indices, luster can be a useful observational feature to identify. The appearance of a gemstone’s fractures when they reflect light is referred to as their fracture luster. This may differ slightly from its base luster in some species. Sub-adamantine fracture, for example, may occur in vitreous spinel. Additionally, the gypsum would display a silky luster if it was found in aggregates of long fibers. So, it’s possible that luster won’t be a helpful diagnostic feature for recognizing gypsum or other gemstones!

Topaz is one of the world's most popular coloured gemstones. It's a hard gemstone with excellent clarity offering extremely good value for money. Sheila's designs use blue topaz of which there are three different types: Sky Topaz is a pale blue stone, Swiss Topaz is a mid bright blue and London Topaz is a darker blue. The bright Swiss Blue Topaz, reminiscent of a blue ocean, is the type used in our designs. If you like blue topaz Sheila has incorporated it in collections such as Reef Knot, and in her Tidal pendant and earrings. Peridot The science of gemstones is called gemology, and you could spend the rest of your life researching just one gem and still not know everything there is to know about it. Every gemstone has a fascinating and unique history, from its formation millions of years ago to its journey from the mine to your home. We’re always aware that new customers are joining us and starting their jewelry and gemstone collections, so we wanted to put together a beginner’s guide for anyone taking their first steps into the fascinating world of gemstones, which we’re delighted to present to you here. Whether you’re new to Gemporia or are joining us for the first time, we hope you find the following information informative and interesting.

The round brilliant cut is the most popular. The fascination with this gem cut is its “fire,” or striking brightness. Do jewelers cut gemstones? There are only four stones in the world classified as precious gemstones and we are proud to say we use them all in our jewellery and rings. The “Big Four” are: Diamond Mined for thousands of years, Sapphire features a delicious deep cornflower blue hue. Other colors exist too and are known as ‘Fancy Sapphires’. Refraction occurs when light travels from the air into a denser material. As light passes from the air into the denser material of the gemstone, it is bent. The amount of bending depends upon the refractive index of the material. High refractive index materials bend the light more. Diamond has an RI of 2.42 and quartz an RI of 1.54. The higher the refractive index, the greater the dispersion, giving more fire. The bending of the light also leads to more internal reflection giving a greater degree of sparkle. Because gems can be cut by hand or machine, there is a variable level of quality. Small asymmetries are common, causing gems to tend to have lower value. Poor placement can cause facets to be off-count or have uneven meet points. While beauty is in the eye of the beholder, the deviations from standard cuts have names.

Designed for beginners and experienced collectors alike, this gemology book explores what gemstones are, how they are classified, and how to identify them by their physical and optical properties. It also shows you how they were fashioned and imitated throughout history. Learn the differences between varieties of cut and uncut stones, organic gemstones, and precious metals. It includes a glossary for many more technical and scientific terms and over 800 high-quality photos of gems. It's the ideal gift for any budding gemologist This color changing miracle was first discovered in Russia in 1830. The original mine has long since been depleted, but we still source a variety from India. There are many beautiful red gemstones, and Ruby is the king of them all. A deep, vibrant red with pink undertones makes this a must-have.Gemstone luster is the way a stone looks when light hits it. It’s usually described as how “bright” or “shiny” a stone appears. It is derived from the Latin word “lux”, meaning “light”. Luster is affected by the stone’s surface as well as its internal structure. The more light that is able to reflect off of the surface of the gemstone, the higher the luster will be. The first section of the book focuses on precious gems in their many forms, with illustrations of priceless jewelry. Practical information includes: Faceting perfects the gem’s shape, allowing it to refract the most light inside and reflect the most light outside (also called scintillation). But when you’re not about glitz and glam, non-faceted gemstones are gorgeous alternatives. Why Choose a Faceted Gemstone This opaque greeny-blue stunner often has unusual, natural patterns running through it, and is so famous it has a color named after it.