January 20 – February 18 · Air

Aquarius birthstones

Aquarius carries Amethyst and Garnet in the zodiac tradition.

Amethyst

Composition Silicon dioxide (SiO₂) — quartz coloured by iron and natural irradiation
Hardness · System 7 · Trigonal

Amethyst fades in sunlight. Heat it and it turns yellow — most commercial citrine is heat-treated amethyst.

Traditionally associated with clear thinking, restraint and calm; the classic stone of sobriety.

Garnet

Composition Group of silicate minerals — almandine, pyrope, spessartine and others
Hardness · System 6.5–7.5 · Cubic

Garnet is not one mineral but a family. Almandine gives the familiar deep red; tsavorite garnet is green and rarer than emerald.

Traditionally carried by travellers as a stone of safe return, and long associated with vitality and steady energy.

Sign or month?

Aquarius runs January 20 – February 18, which crosses two calendar months — so the zodiac stone and the monthly birthstone may or may not agree depending on your exact date. Neither system overrules the other; the zodiac one is simply older.

Compare against the monthly chart →

← All zodiac birthstones

Two systems, one birth date

Aquarius spans 2 calendar months, so you have more than one birthstone

Zodiac stones Amethyst, Garnet
Months it covers January and February
Stones of those months Garnet, Amethyst
In both systems Amethyst, Garnet

January 20 – February 18 — so the sign opens in one month and closes in another. Why the two lists never line up →

The split is uneven: 12 days fall in January and 18 in February. So most people with this sign — 60% — are sold the February stone.

Both stones — Amethyst and Garnet — also sit in the monthly list somewhere, which is the usual case.

January Garnet February Amethyst

The stones themselves

Stone Mohs Crystal system Main sources
Amethyst 7 Trigonal Brazil, Uruguay, Zambia
Garnet 6.5–7.5 Cubic India, Brazil, Madagascar

Garnet is the softer at 6.5–7.5 on the Mohs scale — below 7, which means household dust scratches it, so it belongs in earrings or a pendant rather than an everyday ring. What the scale means →

Amethyst

Silicon dioxide (SiO₂) — quartz coloured by iron and natural irradiation Named from the Greek amethystos, "not intoxicated" — Greeks carved drinking cups from it

Garnet

Group of silicate minerals — almandine, pyrope, spessartine and others Used since the Bronze Age; Egyptian garnet inlays date to roughly 3100 BCE