July birthstone
Ruby
The July birthstone is ruby. Ruby and sapphire are the same mineral, corundum; red corundum is called ruby and every other color is called sapphire. At 9 on the Mohs scale it is second only to diamond among common gem materials, which is why so much antique ruby jewelry survives in wearable condition.
- Species
- Corundum, the same mineral as sapphire
- Color range
- Pinkish red to deep purplish red
- Mohs hardness
- 9
- Also this month
- Nothing else on the modern US list
Color is what drives ruby value, far more than clarity. The trade prizes a strong, slightly bluish red with high saturation, and a stone that reads pinkish or brownish sits well below it. Because saturation matters so much, small differences in color mean large differences in price.
Synthetic ruby has existed since the late nineteenth century and was used openly and honestly in period jewelry, especially in Retro pieces from the 1930s and 1940s where large red stones were wanted for scale. A synthetic ruby in a 1940s cocktail ring is not a fake; it is a correct material choice for that piece. What matters is that the description says which it is, and ours always does.
Heat treatment to improve color and clarity is common and long established. Glass filling of surface fractures is a much more recent and far more significant treatment, and it changes both the value and the way the stone must be cleaned.
In antique and vintage jewelry
Calibre cut rubies channel set in Art Deco platinum, cabochons in Retro gold, small rubies as accents around a diamond cluster, and Victorian gypsy set rings.
Wearing and caring for it
Ruby is hard and takes daily wear well. Warm water, mild soap and a soft brush is enough. The exception is any stone that has been fracture filled, which must be kept away from ultrasonic cleaners, heat and acids.
As a gift
The traditional fortieth anniversary stone, and a strong choice when you want color that carries across a room. Retro pieces with large stones give the most visual impact for the money.
Common questions
What is the difference between a ruby and a pink sapphire?
Only the color threshold, and it is a matter of trade judgment rather than chemistry. Both are corundum colored by chromium; a stone the trade reads as red is a ruby, and a lighter one is a pink sapphire.
Are synthetic rubies in vintage jewelry a problem?
Not in themselves. Synthetics were used openly from the early twentieth century, particularly in Retro pieces. The problem is only when a description hides it, which is why our gemologist identifies every red stone before a piece is listed.
Is ruby suitable for an engagement ring?
Yes. At 9 on the Mohs scale it is one of the most durable colored stones and stands up to daily wear as well as sapphire.
Shop the pieces
Shop ruby jewelry
Antique and vintage pieces set with ruby, each one a single example.
Nothing matching this is available right now. Every piece is a single example and sells once, so this changes weekly. Browse everything in stock or ask our buyers to look for it.