PHYSICAL AND OPTICAL PROPERTIES OF Sapphire
Sapphire, like ruby, is a variety of corundum. This mineral is an aluminum oxide of Al2 O3 chemical composition. Sapphire can be in many colors depending on the coloring elements it contains iron and titanium for blue stones, iron for yellow and green, vanadium for violets, chrome for pink …
Its crystalline system is trigonal. Its hardness is very high: 9 on the Mohs scale which comprises ten grades, the highest of which corresponds to diamonds. It has a density of 3.95 to 4.03, its brightness is glassy, and its pleochroism is strong. Some sapphires have no luminescence, others have an apricot color.
THE COLORS OF SAPPHIRE
All varieties of corundum that are not red are placed in the sapphire category, including leuco-sapphire, colorless, and padparadscha, an incredible hue between pink and orange: its name comes from a word Sanskrit meaning lotus flower…
Blue sapphire is the best known. Light blue, blue-gray, dark blue, all shades are possible. Royal Blue and Cornflower Blue have a deep hue and are very popular.
Pink sapphire goes from pastel to bright pink, and the most valuable ones are the ones that shoot the least to purple.
The yellow sapphire is not the most sought after because it is often less brilliant and clear than the others.
Green sapphires are also not popular; their color is less beautiful than other green gems.
Orange sapphires are very rare, and you have to be careful: most of the ones on the market are tinted stones unless you have an adequate certificate.
The sapphires of a bright purple are very popular because they are rare, especially in large dimensions.
MAIN DEPOSITS OF SAPPHIRES
Sapphire is formed either in magmatic rocks or in the frontier zones between pegmatites (main constituents of the Earth’s mantle) and adjacent rocks, and finally in metamorphic rocks such as gneiss and mica schists. Sapphires can be found in the alluvium, having resisted the erosion of the rocks which sheltered them.
Sapphire is more common than its twin ruby. They are found all over the world, for example in Australia, Brazil, Madagascar. The most important deposits and those containing the most beautiful stones are generally in Asia: the mines of Kashmir, in India, in Sri Lanka where cornflower (blueberry color) is produced, in the mines of Mogok in Burma…
THE ADVICE OF OUR GEMOLOGIST: HOW TO CHOOSE SAPPHIRE?
To choose your sapphire, you have to be attentive to several criteria:
- The color: the sapphire must be a beautiful deep blue and deep, without being too dark because it would reduce its transparency. You should also know that sapphires lose some of their glow under an incandescent lamp, while they reveal all their brilliance in the light of the sun.
- Transparency: sapphires generally have fewer inclusions than rubies. It is better to prefer a stone for greater clarity, even if a light veil, called “silk”, can have its charm.
- Size: it is difficult because the raw sapphire is rarely homogeneous. The lapidary must, therefore, decide in which part he will cut the gem so that it is the most beautiful. The oval cut or the cushion size reveal all the sparkle of the sapphire, but we also find hearts, pears, circles…
Sapphires are often heated to 1300 degrees to intensify their color and reduce the visibility of inclusions.
METALS FREQUENTLY ASSOCIATED WITH SAPPHIRE IN JEWELRY
Most of the time we find frames in yellow gold, pink or white for sapphire, or silver.
STORIES AND LEGENDS AROUND SAPPHIRE
The word sapphire comes from the Hebrew sapphire, which means “the most beautiful thing”. This word finds its roots in the Sanskrit “sauriratna”, passing through Chaldean, Greek and Latin “sapphirus”.
Sapphire has sometimes been confused with lapis lazuli. Thus, some think that the Tables of the Law received by Moses on Mount Sinai were sapphire, others lapis lazuli. This last rock was sometimes called sapphire in Europe, until the twelfth century. The Egyptians associated sapphire with truth and justice.
Charlemagne wore sapphire jewelry which had been offered to him by a caliph in the ninth century. Filigree gold and decorated with precious stones, it was added in the nineteenth century a large sapphire cabochon through which we distinguish what is considered a fragment of the True Cross. This treasure of the cathedral of Reims is preserved in the Palace of Tau.
From the thirteenth century on the decision of Pope Innocent III, the cardinals of the Catholic Church began to wear a ring with a sapphire in the right hand, the one that makes the gesture of blessing.
VIRTUES AND BENEFITS OF SAPPHIRE
Sapphire would have virtues both physically and spiritually.
It would strengthen eyesight, fight fever and stop nosebleeds if applied against the forehead. It would have a beneficial action on hair, skin and, nails, fighting against baldness for example. It would help to treat problems of nervous origin, rheumatism, gout, joint pain.
From a psychic point of view, it symbolizes honesty, truth, fidelity. He would help his wearer to carry out his meditations, to rise spiritually. The medieval saint Hildegarde of Bingen affirmed that by licking it frequently, one could become more intelligent!
ASTROLOGICAL CORRESPONDENCE OF SAPPHIRE
The blue sapphire is especially related to the sign of Libra, by its color of the night which evokes the equinox of autumn. Others associate him with Taurus, helping him to come to terms with himself and listen to his intuition.
In Chinese astrology, he is associated with the Tiger and sometimes bears the name of Third Eye, for his capacity to increase intuition, as for Taurus. Sapphire is the birthstone of September’s children. The sapphire wedding is the 16th anniversary of marriage.