Garnet. It's also the traditional gift for a second wedding anniversary.

Deep red, most often — near-black in shadow and clearly red in direct light, so the stone shifts depending on where you're standing. Garnet is a whole mineral family, though, and it also occurs in green, orange and pink.

Constancy, traditionally — a stone associated with loyalty and with staying the course. Travellers carried garnet as a protective stone for centuries.

It's the one on the modern list, and the one almost everyone means. A few traditional lists add rose quartz, but garnet is the January stone in every standard reference.

Yes. Garnet sits around 7 to 7.5 on the Mohs scale, above quartz and well inside the range for a ring you don't take off. Avoid knocking it against hard surfaces and it will hold.

A garnet piece is personal without being a guess — you only need to know the month. Rings, necklaces and earrings in sterling silver, Silvaria and 18K gold, and orders over $150 arrive in our Experience Box.

Both are red, and at a glance they're easy to confuse. Ruby is a corundum and harder — a 9 on the Mohs scale — with a brighter, slightly pink-leaning red. Garnet runs deeper and darker, closer to wine than to fire, and it's considerably more affordable for the same size of stone.

Not compared with other red stones. A garnet of a size that would cost hundreds in ruby runs a fraction of that, which is why it's one of the few deep red gemstones you can wear every day without thinking about it.