Collection: Turquoise & Tanzanite Jewelry

December claims three birthstones, all of them blue: turquoise, tanzanite, and zircon. They span the entire history of adornment. Turquoise is among the first gems humans ever mined, worn by pharaohs and Persian kings thousands of years before faceting existed. Tanzanite is the newest major gemstone, discovered in 1967 and found in exactly one place on earth. Zircon, the least understood of the three, is a brilliant natural stone whose crystals are literally the oldest dated material on the planet. A December birthday can reach for ancient, brand new, or overlooked, and be right all three times.

Turquoise is opaque, waxy-lustrous, and instantly recognizable, and its finest historical standard is the pure, even sky blue the trade calls Persian blue, traditionally free of the dark veining known as matrix; spiderweb matrix has its own devoted following, particularly in stones from the American Southwest. The Victorians adored turquoise, scattering it across forget-me-not clusters and snake jewelry as a token of remembrance and true love, and those pieces remain some of the most charming things the era made. Because fine turquoise is porous, most modern material is stabilized to protect its color, an accepted practice when disclosed; untreated high-grade turquoise is scarce and prized.

Tanzanite is blue-violet zoisite, found in 1967 in the Merelani Hills below Kilimanjaro in Tanzania, and in nearly sixty years no second source has ever been located. One hillside supplies the world. The stone's signature is pleochroism: it shows blue from one direction, violet from another, sometimes flashes of red, and the cutter's choice of orientation decides each stone's personality. Virtually all tanzanite is gently heated to clear away brown and reveal the blue, a standard and stable practice. Its color rivals fine sapphire at a fraction of the scarcity premium, which is exactly why it earned a place on the modern birthstone list within a generation of being found.

No, and the name collision has been unfair to a beautiful natural stone. Cubic zirconia is a manufactured diamond imitation. Zircon is a natural mineral, zirconium silicate, that has been worn since antiquity, and it carries some of the highest brilliance and fire of any natural gem; well-cut zircons were historically mistaken for diamonds, not the other way around. Blue zircon, the December stone, comes principally from Cambodia and Myanmar and owes its teal-leaning blue to traditional heating. Zircon crystals are also the oldest dated matter on earth, with some grains over four billion years old. A blue zircon in person converts skeptics quickly.