Birthstones and zodiac stones, every system compared
Ask what your birthstone is and most sites give one confident word. That word depends on which of 6 systems they used. There are 4 monthly lists and 2 zodiac lists, from different trade bodies in different decades. They often disagree, yet this site shows all of them side by side, with the source and date behind each one.
This is a reference, not a shop. It documents 48 gemstones with real gemological data: hardness, color family and species. It compares every monthly and zodiac system, month by month and sign by sign. A lookup tool also runs the comparison for any birth date you enter, while every table cites its source.
Two zodiac systems, twelve signs
Two zodiac systems are in active use. They are the traditional tropical zodiac and the modern jewelry-trade convention. Right now, they do not agree on a single sign. The table pulls from the same sourced data as the full comparison, because no one retypes it by hand. Select a sign to see both stones explained.
| Sign | Traditional tropical zodiac | Modern jewelry-trade zodiac |
|---|---|---|
| Aries | Bloodstone | Diamond |
| Taurus | Sapphire | Emerald |
| Gemini | Agate | Pearl |
| Cancer | Emerald | Ruby |
| Leo | Onyx | Peridot |
| Virgo | Carnelian | Sapphire |
| Libra | Chrysolite | Opal |
| Scorpio | Beryl | Topaz |
| Sagittarius | Topaz | Tanzanite |
| Capricorn | Ruby | Garnet |
| Aquarius | Garnet | Amethyst |
| Pisces | Amethyst | Aquamarine |
Explore the reference
There are four ways into the same data, depending on where you start. You can begin from a zodiac sign, a birth month, a specific stone, or just a date.
Zodiac Birthstones
All 12 signs, sign by sign, with sources. We compare the 2 systems that give a stone for each sign: the traditional tropical zodiac and the modern trade convention.
Birthstones
Every calendar month, compared across 4 lists. They run from the pre-1912 historical record to the current US trade chart, so you can see where they agree.
Gemstones
An A–Z reference covering 48 gemstones. It shows Mohs hardness, color family and species, and every stone has its own full page.
Birthstone Finder
Enter a birth date and see what all 6 systems say about it. The answers sit side by side, not collapsed into one.
A look at the collection
Here are six of the 48 stones in the catalog. Every entry shows its mineral family, its hardness and its major sources. It also shows every list that claims the stone as a birthstone.
How we source this
Every stone assignment on this site traces back to a named list. That list may be a trade body, a historical record or a retailer's published convention. Each one shows the year it was set or last revised, where a year exists.
When two systems disagree, we show both, because none is the single correct answer. Each comparison table also carries its own source and retrieval date. We do not use one blanket disclaimer at the bottom of the page.