RUBY: CUT, COLORS, AND Inclusions

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Gemology

Gem-related Field

GENERAL
Some Facts About Ruby
Corundum is a colorless mineral in its purest form. Color differences are caused by trace elements that are part of the mineral's crystal structure. Chromium is the trace element responsible for the red ruby, which can range from orangey red to purplish red. The intensity of ruby red is determined by the amount of chromium present: the more chromium present, the more intense the red hue. Chromium can also generate fluorescence, which intensifies the red color.

The most well-known rubies, such as those found in Myanmar, the Himalayas, and northern Vietnam, are typically created in marble. They are present in the surrounding marble in randomly scattered layers.
All natural rubies have flaws, such as color impurities and rutile needle inclusions known as "silk." These needle inclusions in natural rubies are used by gemologists to identify them from synthetics, simulants, or substitutes.
The Question
What Effect Does Marble Have On The Color Of A Ruby?
Because marble has a low iron concentration, rubies derived from it (referred to as "marble-hosted") lack iron. As a result, many have a bright red color. Furthermore, rubies found in marble frequently fluoresce red under UV light; fluorescence can intensify a ruby's color and boost its worth.

Rubies can also be found in basalt rocks in other sites. These rubies may contain a higher iron concentration, which may cause them to be darker and less vivid. A larger iron content in the chemical constitution of a ruby can also obscure red fluorescence, removing the extra red-colored shine found in rubies encased in marble.
Gemology
Inclusions In Rubies
People in the trade expect rubies to contain some inclusions since rubies without inclusions are nearly impossible to find. The value of a ruby is determined on how apparent the inclusions are. The value of this stone is considerably reduced by obvious defects or inclusions that diminish transparency or brilliance. Inclusions can also reduce a ruby's durability. Significant surface fractures can jeopardize durability.

Thin mineral inclusions known as needles are common characteristics of ruby clarity. Silk is the name given to a mineral that is rutile and contains needles in crossing groups. Ruby can also have needles composed of different minerals, small crystals, areas of color variation, or fingerprint-like inclusions. Certain inclusions can actually improve the beauty of a gemstone. The presence of rutile silk causes light to diffuse onto otherwise dark surfaces. This smoothes the color and spreads it more evenly around the crown of the ruby.
Rubies, like other gemstones, are graded using the four Cs, which stand for color, cut, clarity, and carat weight. Rubies are also valued based on their geographical origin.
GEMOLOGY
The Cut Of A Ruby
A number of factors can affect the cut and proportion of rubies on the market. The crystalline structure of a ruby dictates its suitability for specific cutting. The most typical shape is a flat tabular hexagonal shape, but some ruby crystals can be elongated. The most popular shapes of shaped rubies are ovals and cushions, with shiny crowns of kite-shaped and triangular facets and pavilions cut out with concentric rows of facets to suit these crystal shapes. either rectangular or square.

There are also round and triangular rubies, emeralds, pears, and marquises available. However, these shapes are uncommon in greater sizes and higher grades.

Ruby is incredibly expensive in its natural form, thus cutters try to keep as much weight as possible. They could cut the rubies straight into shallow stones, even if light escapes through flattened pavilions, but it would result in an unappealing section of passage in the stone known as a window.

Another aspect that influences cutting is pleochroism, which is the appearance of distinct colors in different crystal directions. In ruby, the color is typically red to purplish red in one crystal direction and red orange in the other. Cutters can reduce the orange-red tint by placing the table's facet perpendicular to the long crystal's direction. Even yet, because the potential weight loss is too large, it is not always possible to guide a ruby for a perfect color return.Higher grade rubies on one carat are extremely rare, although commercial grade rubies are widely accessible in a variety of sizes. The price per carat of a ruby rises considerably as its size increases.
Unheated Mozambique 4.03 cts Ruby
GEMOLOGY
When Rubies Regain Its Radiance
To commemorate the 50th anniversary of the movie The Wizard of Oz, American jeweler Harry Winston created the iconic pair of ruby-studded shoes worn by child star Judy Garland to traverse the yellow brick road a few years ago. A year later, Van Cleef & Arpels had the brilliant idea of funding the ballet by American Georges Balanchire. Jewels consists of three paintings: diamond, emerald, and, of course, ruby.

The choreographer gained inspiration for his dance while admiring the three windows of the Van Cleef & Arpels boutique on 5th Avenue in New York and spoke with Jacques Arpel.

Boucheron honored this gem, which had a prominent place in the Shah of Iran's treasure, to commemorate the house's 150th anniversary. Finally, De Grisogono made a splash with his Virgin Scarlett ring, which featured a rare ruby weighing 45 carats and was authenticated as coming from the Mogok mine.

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Benjamin Poudevigne
Social Media Manager at GemMatrix
With over ten years of marketing experience, I finally decided to settle down in Bangkok to work in an area that I have always been interested in: the gemstones industry. I'm still learning how the market works on a daily basis, and I enjoy sharing my experience with those who are interested in learning more about gems in general.