Sapphire (Corundum)

Sapphire, a precious variety of the mineral corundum, is treasured for its magnificent blue hues, symbolizing wisdom, royalty, and divine favor. As one of the four cardinal gemstones, its history dates back to ancient civilizations, where it was believed to protect its owner from harm and envy. Its durability and brilliance make it a timeless choice for fine jewelry, representing faithfulness and sincerity.

Mohs Hardness

Origin

Sri Lanka, Myanmar, Kashmir, Thailand, Australia, Madagascar

Market Price Range

Entry-level (under 1 ct, heated): $50 - $500/carat. Commercial-grade (1-3 ct, heated): $500 - $2,000/carat. High-quality (3-5 ct, unheated/minor heat): $3,000 - $20,000/carat. Collector's grade (5+ ct, top origin, unheated): $20,000 - $200,000+/carat.

Detailed Description

Sapphire is the gemstone variety of corundum, an aluminum oxide mineral. While most famously blue, it occurs in a spectrum of 'fancy' colors except for red, which is classified as ruby. The iconic blue color is primarily caused by trace amounts of iron and titanium within the crystal structure. Sapphires have been cherished for millennia, with ancient royalty in Greece and Rome believing they protected their owners from envy and harm. The British Crown Jewels, for instance, feature several prominent sapphires, cementing their association with nobility. When collecting sapphires, origin, color, and treatment are paramount. Stones from Kashmir are legendary for their velvety, cornflower blue hue and are exceedingly rare. Myanmar (Burma) and Sri Lanka (Ceylon) are also famed for producing high-quality gems. Most sapphires on the market are heat-treated to improve their color and clarity, a stable and widely accepted practice. However, untreated sapphires of fine quality command a significant premium, making them a prime target for serious collectors and investors.

Identification Methods

Hardness Test: With a Mohs hardness of 9, second only to diamond, it can easily scratch glass and most metals.

Internal Features: Natural sapphires often exhibit straight, angular color banding and growth lines. Tiny mineral inclusions, like rutile needles creating a 'silk' effect, are common.

Color Distribution: The color in natural stones is often uneven, showing distinct zones of lighter and darker blue parallel to the crystal faces.

Breath Test: Due to its high thermal conductivity, when you breathe on a natural sapphire, the fog will dissipate very quickly.

Professional Examination: Use professional gemological tools like a refractometer and spectroscope to verify its physical and optical properties for a conclusive identification.

Market Information

The sapphire market remains robust, particularly for high-quality, untreated stones from renowned origins like Kashmir, Myanmar, and Sri Lanka, which continue to see steady price appreciation. The value of these top-tier gems is driven by their rarity and collector demand. The commercial-grade market is more stable, while demand for lower-end, smaller stones can fluctuate. Investment-grade sapphires are typically those over 3 carats, with exceptional color and clarity, and no heat treatment.