Small pear-cut stones of lab-grown zultanite, each about 3 x 5 mm, follow one another all the way around this tennis bracelet in gold-plated sterling silver. Against the warm yellow of the metal they look smoky olive, and because zultanite is a color-change stone, their tone shifts when you step out of daylight into lamp light. The gold frame stays the same all day; the stones are the part that moves.

Zultanite is the trade name for color-change diaspore, a gem mined in the mountains of Anatolia, and you may also see it called Turkish diaspore or sultanite. The stones in this bracelet are lab-grown zultanite, not mined, and they are stabilized.

Each pear sits in its own prong setting, and the settings are linked one after another, so the band bends with the wrist as an unbroken line of stones, the way a tennis bracelet should. We cast it in 925 sterling silver, plate it in yellow gold and finish it by hand in our workshop in Türkiye. The surface is polished. This is a gold-plated tennis bracelet, a layer of gold over sterling silver rather than solid gold.

It weighs about 5.1 grams, and with stones only 3 mm across it wears as a thin, 3mm tennis bracelet. That makes it easy to stack with other gold-tone bracelets or next to a watch, and easy to forget you have it on at a desk. The bracelet is 20 cm long and closes with a lobster clasp; a short extender chain on the other side lets you wear it a little closer to the wrist or a little looser.

As a gemstone tennis bracelet for women it suits a wife or girlfriend who would rather have a stone that changes through the evening than another clear sparkle, and it works as a Christmas or anniversary gift as easily as an everyday piece kept for herself.