Spécial du mois de novembre; Création bague
Un voyage dans l’univers distinct de l’aigue-marine sous le prisme de la gemmologiste.
Bienvenue dans mon laboratoire.
Aquamarine’s name comes from the Latin for seawater and it was said to calm waves and keep sailors safe at sea. March’s birthstone was also thought to enhance the happiness of marriages. The best gems combine high clarity with limpid transparency and blue to slightly greenish blue hues. Like many beryls, aquamarine forms large crystals suitable for sizable fashioned gems and carvings.
Aquamarine is the birthstone for March and the gem of the 19th wedding anniversary.
The largest gem-quality aquamarine crystal mined to date is 19 inches long.
Like emerald, aquamarine is a color variety of the mineral beryl.
Aquamarine is mined at high elevations in Pakistan’s Karakoram Mountains.
- MINERAL: beryl
- CHEMISTRY: Be3Al2Si6O18
- COLOR: greenish blue, light in tone
- REFRACTIVE INDEX: 1.577 to 1.583
- BIREFRINGENCE: 0.005 to 0.009
- SPECIFIC GRAVITY: 2.72
- MOHS HARDNESS: 7.5 to 8.0
Ruby is the most valuable variety of the corundum mineral species, which also includes sapphire. Rubies can command the highest per-carat price of any colored stone. This makes ruby one of the most important gems in the colored stone market.
In its purest form, the mineral corundum is colorless. Trace elements that become part of the mineral’s crystal structure cause variations in its color. Chromium is the trace element that causes ruby’s red, which ranges from an orangy red to a purplish red.
The strength of ruby’s red depends on how much chromium is present—the more chromium, the stronger the red color. Chromium can also cause fluorescence, which adds to the intensity of the red color.
The most renowned rubies, like those from Myanmar, the Himalayas, and northern Vietnam, typically form in marble. They’re found in layers that are distributed irregularly within the surrounding marble. Marble forms as part of the metamorphic (rock-altering) process, when heat and pressure from mountain formation act on existing limestone deposits.
Red is the color of our most intense emotions—love and anger, passion and fury. It’s associated with objects of power and desire—like fast cars and red roses. Early cultures treasured rubies for their similarity to the redness of the blood that flowed through their veins, and believed that rubies held the power of life.
Ruby is one of the most historically significant colored stones. Rubies are mentioned four times in the Bible, in association with attributes like beauty and wisdom. In the ancient language of Sanskrit, ruby is called ratnaraj, or “king of precious stones.”
In the first century AD, the Roman scholar Pliny included rubies in his Natural History, describing their hardness and density. Ancient Hindus believed that those who offered fine rubies to the god Krishna were granted rebirth as emperors.
Hindus divided ruby into four castes, calling the true Oriental ruby a Brahmin. Someone in possession of a Brahmin was believed to have the advantage of perfect safety.
Ruby has accumulated a host of legends over the centuries. People in India believed that rubies enabled their owners to live in peace with their enemies. In Burma (a ruby source since at least 600 AD—now called Myanmar), warriors possessed rubies to make them invincible in battle. However, it wasn’t enough to just wear the rubies. They had to insert them into their flesh and make them part of their bodies.
The name ruby comes from the Latin word ruber, which means “red.” The glowing red of ruby suggested an inextinguishable flame burning in the stone, even shining through clothing and able to boil water.
Ruby has been called the most precious of the 12 stones created by God.
Ruby retained its importance with the birth of the western world and became one of the most sought-after gems of European royalty and the upper classes. Many medieval Europeans wore rubies to guarantee health, wealth, wisdom, and success in love.
Desire for ruby is just as great today as it always has been. As a symbol of passion, ruby makes an ideal romantic gift. Consumers are drawn to the lush color because it also signifies wealth and success.
In Sanskrit, ruby is ratnaraj, meaning the king of gems.
Myanmar’s legendary valley of rubies; the source of many of the world’s most fabulous gems.
On May 12, 2015, a 25.59-carat ruby ring sold for $1,266,901 per carat, setting a new record at auction for a colored gemstone.
Cat’s eye in alexandrite!
Alexandrite, with its chameleon-like qualities, is a rare variety of the mineral chrysoberyl. Its color can be a lovely green in daylight or fluorescent light, changing to brownish or purplish red in the incandescent light from a lamp or candle flame. This is a result of the complex way the mineral absorbs light.
Alexandrite’s dramatic color change is sometimes described as “emerald by day, ruby by night.” Other gems also change color in response to a light-source change, but this gem’s transformation is so striking that the phenomenon itself is often called “the alexandrite effect.”
Typically, its three pleochroic colors are green, orange, and purple-red. However, the striking color change doesn’t arise from the gem’s pleochroism, but rather from the mineral’s unusual light-absorbing properties.
Because of its scarcity, especially in larger sizes, alexandrite is a relatively expensive member of the chrysoberyl family. It shares its status as a June birthstone with cultured pearl and moonstone.
The year alexandrite was discovered in Russia’s Ural Mountains.