What Is My Zodiac Stone?
Gemini Birthstone & Crystals: Agate
♊ May 21 – June 20 · Agate
Gemini is the Mercury-ruled air sign of the twins, quick-thinking, sociable and easily bored. Agate is both its modern and traditional stone: a banded chalcedony that comes in endless patterns and colors, which suits a sign famous for having more than one side.
Pearl, the June birthstone, overlaps most Gemini birthdays and is often paired with the sign for calm. Citrine is the classic pick for Gemini's communication and ideas, and tiger's eye is traditionally carried to help a scattered mind commit to one thing at a time.
Gemini at a glance
- Dates: May 21 – June 20
- Element: Air · Ruled by Mercury
- Primary stone: Agate
- Traditional stone: Agate
- Supporting crystals: Pearl, Citrine, Tiger's Eye
- Often described as curious, witty, adaptable, restless
How Geminis traditionally use their stones
- Agate as a worry stone during long conversations or negotiations.
- Citrine at your workspace when you need ideas to flow.
- Tiger's eye when you have too many options and need to pick one.
About Agate
Agate is a banded variety of chalcedony formed in concentric layers in volcanic rocks. Each layer represents a different period of mineral deposition.
| Type | Quartz Family |
|---|---|
| Chemical formula | SiO2 |
| Mohs hardness | 7 |
| Crystal system | hexagonal |
| Luster | waxy |
| Streak | White |
| Cleavage | None |
- Named after the Achates River in Sicily
- Some agates have been forming for millions of years
- Dyed agates have been made since Roman times
How to tell real Agate at a glance
- Color: Banded, Blue, Brown, Red, Green, Gray. Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue.
- Luster: Waxy. Compare a fresh surface with glass and metal; this luster is softer than either.
- Transparency: Translucent. Hold a thin edge up to a bright light and note whether light passes through.
- Mohs hardness: 7. It scratches glass and a steel knife and cannot be scratched by a steel file.
Other stones on this page
Frequently asked questions
What is the Gemini birthstone?
Agate is the traditional and modern Gemini stone. Pearl (June), emerald (May), citrine and tiger's eye are also associated with the sign.
What are the Gemini dates?
Gemini runs from May 21 – June 20. Cusp dates can shift by a day depending on the year and your time zone; if you were born on the boundary, check your birth time.
Can I wear a stone that isn't my zodiac stone?
Of course. Zodiac stone lists are traditions, not rules. Pick the stone whose look and story you like, then use StoneSnap's identify guides to make sure it is the real thing.
