Birthstones / August
August: Peridot, Spinel
Traditional: Sardonyx, Peridot · Yellow-green (peridot); red, pink, blue, black (spinel) · Mohs 6.5 to 7 (peridot); 8 (spinel)
What it is
Peridot is gem olivine, one of the few gems in a single color and almost never treated; from Arizona, Pakistan and Myanmar. Spinel, added in 2016, is a hard oxide in many colors, rarely treated, and the stone behind several historic 'rubies' in crown jewels. Black spinel is the affordable form.
Care
Soap and water. Peridot is softer, so avoid knocks and hard scrubbing.
Before you buy
Peridot: a strong grass-green without brown is the grade to look for. Spinel: red and cobalt blue are expensive; black and grey are not.
Sources: Jewelers of America modern birthstone list; GIA gem encyclopedia; FTC Jewelry Guides on treatment and lab-growth disclosure. Clasp & Lens does not appraise or grade stones; what a listing says is the supplier's statement.