The sapphire: a stone with history
It is said that Moses received the Ten Commandments on a sapphire tablet. Thanks to a few more mentions of the stone in the Bible, it later became a bishop's ring.
The Persians also knew the sapphire. They believed that the sky was reflected in the blue of the sapphires. Numerous other mythological and religious traditions show that the sapphire has been a well-known and coveted gemstone for a very long time.
The sapphire and its colors
Like the ruby, sapphires are also corundum. Originally, only blue corundum was classified as a sapphire. Now, however, sapphires are also known to occur in other colors: they can be white, pink, violet, yellow, orange or green.
Corundum is a mineral that can contain traces of various metals. These metals can be iron, titanium, copper, chromium or magnesium. Depending on the presence and quantity of the metals, the sapphire takes on a different color.
The effect of color on price
Pink sapphires are often difficult to distinguish from rubies, even for experts. Sometimes this is simply because the color nuances cannot be clearly assigned. In terms of price, however, the distinction plays an important role: a ruby is more expensive than a pink sapphire.
The pinkish-orange Padparadscha is also often the subject of doubt. Its color is not precisely defined and repeatedly sparks debate. The classification is important because high-quality Padparadschas can even fetch higher prices than some blue sapphires.
Corundums are valuable stones, with rubies being the most valuable, followed by blue sapphires, Padparadschas and pink sapphires. For the others, color plays a subordinate role.
Use: sapphires as an investment, for jewelry and industrial applications
Valuable sapphires are popular investments and can be stored as individual stones or set in pieces of jewelry. High-quality workmanship by a goldsmith can further increase the value of the stone.
Jewelry in all colors of the rainbow
Thanks to their extreme hardness (9 on the Mohs scale), sapphires are suitable for all types of jewelry: from brooches to earrings and necklaces to finely crafted rings. Thanks to the many colors, there is a wide range of possible combinations. While blue sapphires are often combined with diamonds, white gold and silver, pink sapphires, padparadscha and yellow sapphires are often framed in gold.
Combining sapphires of different colors is also popular. The wide range of colors gives rings, bracelets and the like a playful rainbow look.
Incidentally, if you are still looking for the ideal stone for those born in September, you should consider the sapphire: according to the American Gem Society, it is the birthstone for those born in September. Sapphire gemstones also symbolize loyalty, nobility, sincerity and integrity.
Industrial applications
Sapphires are not only valued as jewelry. They are also used in scientific instruments, watches and electronics.
Origin & mines of sapphires
Sapphires are mined in India, Myanmar, Thailand, Vietnam, Sri Lanka, China, Australia, Brazil, Africa (including Madagascar) and North America (mainly in Montana).
The mining sites also affect the price. Blue sapphires are particularly valuable when they come from Kashmir. This is partly due to the good quality of these stones, and partly because the mines there have already been depleted.
Normally, sapphires are mined by hand in small mines.
Hardness and inclusions of sapphires
Sapphire has a hardness of 9 on the Mohs scale. It is only one degree softer than diamond, which is considered the hardest precious stone. Many sapphires have fine rutile inclusions. In special cases, these rutile inclusions lead to optical phenomena such as the asterism in the star sapphire. The reflection of light on the needles parallel to the axes results in a six-pointed “star”. The cabochon cut is used for stones like this. In such cases, the inclusions can increase the value of the gemstone. However, if the inclusions are of a different shape, this usually results in a reduction in value.
Treatment
Sapphires are often heat-treated. This means that they are heated in a furnace. A distinction is made between low-temperature and high-temperature heating. Heating at a low temperature is difficult to detect, unlike heating at a high temperature. Heating improves the color.
Even though heat treatment is a common treatment for sapphires, it affects the price. A beautiful untreated sapphire will always be more expensive than a treated one.
It is therefore important that the degree of treatment is also indicated in the certificate.
Most common cuts
Raw crystals have certain shapes that depend, among other things, on the mineral. In this case, the mineral is corundum. The most common shapes are oval, cushion, cabochon, emerald and round.
Which cut is used depends primarily on the material. If the material is good, the cutter is usually given the task of cutting large stones out of the rough. This results in stones with as many carats as possible. This type of cutting leads to symmetry errors. Such an asymmetrical cut is also called a “native cut”.
A lot of material is lost during the highly symmetrical cutting process, which is why these sapphires cost more than stones in a native cut. An experienced goldsmith can place the cut stone in the piece of jewelry in such a way that any imperfections in symmetry are hidden from the eye of the beholder.
