What Is My Birthstone?
July Birthstone: Ruby
Ruby
Ruby is the July birthstone, the red variety of corundum and sister to sapphire. Chromium gives ruby its color, and the finest stones show a pure, slightly purplish red that Burmese traders called pigeon's blood.
At Mohs 9 ruby is second only to diamond in hardness, so it wears beautifully in rings. Large clean rubies are rarer than diamonds of the same size, which is why top rubies set record prices at auction.
Carnelian and onyx appear on older birthstone lists for July and make inexpensive, opaque alternatives to ruby's saturated red.
July birthstones at a glance
- Modern birthstone: Ruby
- Traditional birthstone: Ruby
- Alternates: Carnelian, Onyx
- Color: red
- Traditionally associated with passion, vitality and protection
About Ruby
Ruby is a red variety of corundum, the second hardest natural mineral. Its intense red color comes from chromium impurities.
| Type | Precious Stones |
|---|---|
| Chemical formula | Al2O3 |
| Mohs hardness | 9 |
| Crystal system | trigonal |
| Luster | adamantine |
| Streak | White |
| Cleavage | None |
- The most valuable rubies are 'pigeon blood' red from Myanmar
- Rubies and sapphires are the same mineral, just different colors
- Ancient warriors implanted rubies in their skin for protection
How to tell real Ruby at a glance
- Color: Red, Pinkish Red, Purplish Red. Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue.
- Luster: Adamantine. Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner.
- Transparency: Transparent. Hold a thin edge up to a bright light and note whether light passes through.
- Mohs hardness: 9. It scratches glass, steel and even quartz; only harder gems will mark it.
Other stones on this page
Frequently asked questions
What is the birthstone for July?
The modern July birthstone is Ruby. Carnelian, Onyx are also used.
What color is the July birthstone?
Ruby is red.
What is the difference between ruby and red sapphire?
They are the same mineral, corundum. Gem labs call medium-to-dark red stones ruby and lighter or pinkish stones pink sapphire; the dividing line varies by country.
How can I tell ruby from garnet?
Ruby is much harder (9 vs about 7), often shows silk-like needle inclusions, and glows red under UV light. Garnet does not fluoresce and is slightly denser.
