DeltaGem Star Sapphire Medal
Added: (Mon Jul 25 2022)
Pressbox (Press Release) -
STAR SAPPHIRE:
Star sapphires and star rubies belong to the phenomenal corundum category. The star effect is called asterism. It’s caused by reflections from tiny, needle-like inclusions that are oriented in several specific directions. Stars are usually made up of 2, 3, or 6 intersecting bands, resulting in 4, 6, or (rarely) 12 rays.
A star sapphire is a type of sapphire that exhibits a star-like phenomenon known as asterism; red stones are known as "star rubies".
Star sapphires contain intersecting needle-like inclusions following the underlying crystal structure that causes the appearance of a six-rayed "star"-shaped pattern when viewed with a single overhead light source. The inclusion is often the mineral rutile, a mineral composed primarily of titanium dioxide.
The stones are cut en cabochon, typically with the center of the star near the top of the dome.
The inclusions can alternatively produce a cat's eye effect if the girdle plane of the cabochon is oriented parallel to the crystal's c-axis rather than perpendicular to it.
A rare variety of natural sapphire, known as color-change sapphire, exhibits different colors in different light. Color change sapphires are blue in outdoor light and purple under incandescent indoor light, or green to gray-green in daylight and pink to reddish-violet in incandescent light. Color change sapphires come from a variety of locations, including Madagascar, Myanmar, Sri Lanka and Tanzania. Two types exist. The first features the chromium chromophore that creates the red color of ruby, combined with the iron + titanium chromophore that produces the blue color in sapphire. A rarer type, which comes from the Mogok area of Myanmar, features a vanadium chromophore, the same as is used in Verneuil synthetic color-change sapphire.
COLOR :
Star sapphire can be purple, pink, blue, black, gray, brown, white, or yellow—practically every color under the sun.
The term “star sapphire” encompasses all colors of star corundum except red, which is called star ruby.
Naturally, some colors of star corundum are valued more highly than others.
THE LARGEST STAR-SAPPHIRES IN THE WORLD :
-1 At 1404.49 carats, The Star of Adam is the largest known blue star sapphire. The gem was mined in the city of Ratnapura, southern Sri Lanka.
-2 The Black Star of Queensland, the second largest star sapphire in the world, weighs 733 carats.
-3 The Star of India mined in Sri Lanka and weighing 563.4 carats is thought to be the third-largest star sapphire, and is currently on display at the American Museum of Natural History in New York City.
-4 The DELTA GEM Medal weighs 239.35 carats and is the fourth largest natural star sapphire in the world.
-5 The 182-carat Star of Bombay, mined in Sri Lanka and located in the National Museum of Natural History in Washington, D.C., is another example of a large blue star sapphire.
DELTA GEM Star sapphire Medal
This gem weighs 239.5 carats and is the fourth largest natural star sapphire in the world.
Its initial weight was 250.40 carats, which was polished by Delta Gem Company gemologist in 2018 As a result of which its weight was reduced to 239.35 carats and is consisted of 35.608 gr white gold and 58 pieces of diamond (1.66 carats) in medal from.
The geometric shape of the star on this gem is very beautiful, precise and regular.
This gem is very exquisite and unique.
It is difficult to put a price on this jewelry. In fact, due to the uniqueness of the gem, no specific price can be set for it. The value of the jewelry, however, is estimated by DELTA GEM gemologists to be around 400,000£.