Ruby

Ruby and sapphire are both corundum. When corundum is red, colored by chromium, it is ruby; every other color is sapphire.

It lasts. Ruby is 9 on the Mohs scale, its toughness is excellent and it has no cleavage, so it can be worn every day, in prongs, a bezel or a halo.

The red, and a July birthday.

Ask what has been done to the stone. Heating is the common treatment; others include lattice diffusion and lead-glass fracture filling, which is more common in ruby than in sapphire. In the United States, a treatment has to be disclosed when it isn’t permanent, needs special care or significantly affects value.

A fracture-filled ruby needs gentler cleaning, and a laboratory-grown ruby has to be labeled as such in the United States, so ask whether a stone is natural or laboratory-grown.

Anyone who wants a red stone in a ring worn every day, anyone with a July birthday, and anyone who wants a colored stone beside diamonds.

The Design Studio sets a ruby from 4 to 12 mm long in any of its shapes and shows its millimeters and an approximate weight. By the studio’s figures, corundum (specific gravity 4.0) weighs about 1.1 times a diamond (3.52) of the same size.

What moves a ruby’s cost: its size, its color and clarity, any treatment, and whether it is natural or laboratory-grown; then the metal and the setting. Sara quotes the finished piece after a consultation.

Warm soapy water and a soft brush are safe. Ultrasonic and steam cleaners are usually safe for an untreated or heated ruby, but not for one that is fracture-filled, cavity-filled or dyed, so it helps to know which yours is. Pacific Jewel rings come back to Sara for a clean and an inspection whenever you like.