March 21 – April 19 · Fire

Aries birthstones

Aries carries Diamond and Bloodstone in the zodiac tradition.

Diamond

Composition Pure carbon (C) in cubic crystal structure
Hardness · System 10 · Cubic

The hardest natural substance — but hardness is not toughness. A diamond will scratch anything, and still cleave if struck along its grain.

Traditionally associated with clarity, permanence and commitment.

Bloodstone

Composition Chalcedony (cryptocrystalline quartz) with inclusions of red iron oxide
Hardness · System 6.5–7 · Trigonal

The red spots are iron oxide, not blood — but the resemblance drove nearly all of its folklore.

Traditionally carried for courage and endurance, particularly by athletes and soldiers.

Sign or month?

Aries runs March 21 – April 19, 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

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

Zodiac stones Diamond, Bloodstone
Months it covers March and April
Stones of those months Aquamarine, Diamond
In both systems Diamond

March 21 – April 19 — so the sign opens in one month and closes in another. Why the two lists never line up →

The split is uneven: 11 days fall in March and 19 in April. So most people with this sign — 63% — are sold the April stone.

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

March Aquamarine April Diamond

The stones themselves

Stone Mohs Crystal system Main sources
Diamond 10 Cubic Botswana, Russia, Canada
Bloodstone 6.5–7 Trigonal India, Brazil, Australia

Bloodstone is the softer at 6.5–7 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 →

Diamond

Pure carbon (C) in cubic crystal structure First mined in India before 400 BCE; the word comes from the Greek adamas, "unbreakable"

Bloodstone

Chalcedony (cryptocrystalline quartz) with inclusions of red iron oxide Known to the Romans as heliotrope; the red flecks gave rise to medieval Christian legend