Guide to Gems: Illustrated Guide to the Identification, Properties and Use of Gemstones (Firefly Pocket)

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Some gemstones, such as amethysts, may have a secondary colour - in the case of amethyst, red, some types of garnet flash yellow or orange. A mineral form of iron oxide, this stone is red when cut or powdered, and its name comes from the Greek for “blood”. Unlike other precious and semi-precious stones, hematite is opaque and does not diffract light. Its surface has a magnificent metallic shine and it can look similar to silver when polished. Sheila has used polished hematite stones in several pieces inspired by Orkney’s history such as her Ogham cufflinks, Runic torque bangle and magnificent Celtic penannular brooch. Onyx

Gemstone luster is one of the most important factors to consider when purchasing a gemstone. It can be difficult to understand, but this guide will explain everything you need to know about how gemstones shine. We’ll discuss the different types of luster, as well as how to spot quality stones based on their luster. Let’s get started!The symmetry and proportion of each flat, polished plane is what contributes to (or detracts from) a gem’s sparkling brilliance. Faceting all but guarantees the gem’s performance as a stunner. Essentially, forging its facets by hand (or machine) increases the gem’s “fire,” meaning you’re getting the most light possible from your stone. Honing in on how light enters and exits your gem ensures its brightest — and subjectively best — appearance. For transparent gems, this often means greater clarity. Parts of a Faceted Gemstone Famously a deep red, dark-toned stone, Garnet has also been discovered in a plethora of colors including green, orange and yellow. Some gem species’ lusters may be referred to as ranges. For example, serpentines may have resinous, pearly, or waxy lusters. Sphalerites can range from resinous to even adamantine. In addition, some gemstone lusters have “sub-types.” These terms describe gems that are close to the main luster type.

Brilliant, step, and rose cuts are the staple gem cut designs. Each cut style has a certain number of facets, or flat planes, to define a gem’s shape and pattern. Cuts are used to create a more brilliant or colorful gem. What does cut mean for gems? As the name suggests, gems with a waxy luster appear to have a layer of wax on their surface. Jade, chalcedony, and Turquoise have a waxy luster. Some Opals are also considered to have a waxy luster, though this can sometimes be polished to a resinous finish. Like opals, moonstones diffract light and this visual effect gave rise to the stone’s name. Moonstone has been used in jewellery and rings since ancient times and is associated with the power and mystery of the moon. We source the top grade moonstone colour known as fine blue and this is one of Sheila’s favourite stones. Sheila uses moonstone to embellish her designs like droplets of water. It graces her popular Morning Dew, Moonlight, Rowan and Wild Grasses collections. Pearl It’s not always about numbers. With a round base and fewer facets, a rose cut’s beauty is more about subtlety than shine. But if you’re interested in numbers, this gem cut has been around since the 16th century, making it an oldie, but a goodie. With layers of facets that unfurl like a flower, it’s pure romance. Gypsum, for instance, may have a pearly luster on surfaces parallel to the cleavage yet a vitreous luster on some crystal faces.The first section of the book focuses on precious gems in their many forms, with illustrations of priceless jewelry. Practical information includes: The visual beauty of gemstones is related to five main factors. Those factors are as follows: Lustre (or Luster), Brilliance, Dispersion, Refraction and Scintillation. The variances between these factors give a precious stone its appeal. Most people buying fine jewellery know little to nothing about these factors. Knowing even a little will help you make more confident choices about the jewellery you buy and wear. There are many hard to read textbooks on these topics - but they can be left to the real experts! This article covers only the necessary basics. A gemstone’s polish luster, or how it appears after polishing, can be very different from its base luster. For instance, polishing can turn jet, which has a dull or waxy base luster, into vitreous.

A fascinating profile of each gem is accompanied with color photographs of the raw crystal, common cuts, and finally polished for use in jewelry. At-a-glance charts provide technical details such as refractive index, crystal group, luster, hardness and cleavage for each gem. Traditionally found either colorless or in imperial yellow hues, recent advancements in technology have allowed us to bring you Topaz in a variety of fantastic colors. A gem cut is its intricate design. Cutting sculpts a gem from its initial roughness or smoothness to improve its appearance and make it more desirable as a piece of jewelry. What is a modified cut?

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 The most famous gem of them all? Almost certainly, and all thanks to its remarkable fire, effortless brilliance and clarity to die for. Essential.