July's birthstone is the ruby, a red to purplish red corundum that rates 9 on the Mohs scale, second only to diamond among birthstones.
Ruby has belonged to July since the first American list in 1912, and it remains the month's only stone in the United States. A deep red gem sits comfortably in the hottest part of the year, and the color itself gave ruby its name. Its mineral, corundum, also produces sapphire, the September birthstone, so the two months share a single species that is divided by color alone.
The name comes from the Latin ruber, red. In ancient India ruby was called the king of precious stones, and it has long served as a symbol of power, passion and love. That reputation carries into modern custom as well: ruby appears on the anniversary calendar twice, for the 15th and the 40th years of marriage, which keeps it tied to milestones as well as birthdays.
Ruby is red corundum, with colors ranging from pure red to purplish red. At 9 on the Mohs scale it ties with sapphire as the hardest birthstone after diamond. Myanmar leads a long list of notable sources that includes Mozambique, Vietnam, Thailand, Afghanistan, Tajikistan, Pakistan, Sri Lanka, Kenya, Tanzania and Madagascar. Treatment matters: heated stones clean like untreated ones, but glass-filled rubies need far gentler handling.
For untreated or heat-treated rubies, warm soapy water and a soft brush are safest, and ultrasonic or steam cleaning is usually fine. Glass-filled or dyed stones are another matter: wipe them only with a damp cloth. Ruby's hardness lets it scratch softer gems, so giving it its own compartment spares the rest of a jewelry collection.
| US list | UK list | Japanese list (2021) |
|---|---|---|
| Ruby | Ruby(Carnelian) | RubySphene (titanite) |
Ruby, the red variety of corundum, is July's only birthstone on the American list. The UK's National Association of Jewellers adds carnelian as an alternative.
Both are corundum with a hardness of 9. Red corundum is called ruby, while other colors, including blue, pink, yellow, orange, purple and colorless, are sapphire. That shared mineral links the July and September birthstones.
JanuaryGarnet
FebruaryAmethyst
MarchAquamarine
AprilDiamond
MayEmerald
JunePearlMoonstoneAlexandrite
JulyRuby
AugustPeridotSpinel
SeptemberSapphire
OctoberOpalTourmaline
NovemberTopazCitrine
DecemberTurquoiseTanzaniteZirconBirthstones are a jewelry and cultural tradition, and their meanings are folklore. Gem facts are compiled from public material by GIA, the American Gem Society and Jewelers of America.