Cancer Birthstone: Ruby
The Cancer birthstone is Ruby — the gemstone of the water sign ruled by The Moon.
Dates
Jun 21 – Jul 22
Birthstone
Ruby
Element
Water
Ruling Planet
The Moon
Cancer and the Ruby
Cancer is the zodiac's great nurturer, a water sign ruled by the Moon, and its birthstones run from the fiery heart of the ruby to the cool glow of the moonstone. The ruby brings warmth and protection to a sign that feels everything deeply, while moonstone honours Cancer's lifelong bond with the Moon. Few signs carry such a tender, devoted heart.
Why Ruby suits Cancer
The ruby suits Cancer because beneath its protective shell, the crab holds an intensely passionate, loving core — and the ruby has always been the stone of the heart, worn for love, vitality, and protection. Moonstone, Cancer's spiritual birthstone, glows with adularescence like moonlight on water, mirroring the sign's ruler and its deep emotional intuition. One stone guards Cancer's fire, the other honours its tides.
Cancer traits the Ruby reflects
The Cancer personality
As a cardinal water sign ruled by The Moon, Cancer is known for being nurturing, intuitive, loyal and protective. Water signs feel deeply, guided by emotion, intuition and empathy. A birthstone for Cancer works best when it speaks to those qualities — which is exactly what Ruby does.
That is also why Cancer carries supporting stones alongside Ruby. Where the primary stone captures the sign's headline character, the supporting stones round out the rest of its nature.
Cancer supporting stones
Alongside Ruby, these stones are traditionally linked to Cancer and make thoughtful companions or alternatives.
Moonstone
Ruled by the Moon, Cancer is the natural keeper of moonstone, the stone of intuition, tides, and emotional safety.
Pearl
A soft, water-born gem that mirrors Cancer's nurturing, protective, oceanic nature.
How to wear or gift the Cancer birthstone
Cancer rules the chest and heart, so a ruby or moonstone pendant worn close to the heart suits the sign perfectly. Ruby is hard and durable, ideal for an everyday ring, while moonstone is softer and best kept for pendants and earrings. A piece that combines a warm ruby with a glowing moonstone captures both halves of the Cancer soul — its fire and its moon.
Your monthly birthstone too
Because Cancer runs from Jun 21 – Jul 22, it crosses two calendar months — each with its own monthly birthstone. Depending on the exact day you were born, your monthly stone may differ from your zodiac stone. Here are the month pillars that Cancer overlaps:
Go deeper on the Ruby
Read more about Cancer's stones in these in-depth guides: