How to clean it
Soapy water and a soft cloth. Never ultrasonic — feldspar cleaves easily and vibration can split it.
White to grey with blue sheen
Moonstone
The birthstone for June.
Properties
Composition
Potassium aluminium silicate (KAlSi₃O₈) — feldspar
Hardness (Mohs)
6–6.5
Crystal system
Monoclinic
Colour
White to grey with blue sheen
Mined in
Sri Lanka, India, Madagascar, Myanmar
Worth knowing
The floating blue glow is adularescence — light scattering between microscopic layers of two feldspars, not an inclusion or a coating.
History
Roman naturalists believed it was solidified moonlight.
Practical
Caring for Moonstone
How to tell it is real
Opalite and milky glass are the usual substitutes. Real moonstone shows adularescence that moves as you tilt it; glass shows a static sheen that stays put.
One general rule covers most mistakes: never store stones loose together. Diamond at 10 on the Mohs scale scratches everything else you own, and it does not need much contact to do it.
What that hardness means in practice
Softer than household dust. Better in earrings or a pendant than in a ring, where it takes constant knocks.
Traditional associations
Moonstone is traditionally linked to intuition, cycles and new beginnings. In chakra systems it is placed at the Sacral, Third Eye, and in elemental correspondence it is assigned to Water.
These are cultural associations recorded across various traditions, not claims about physical effects. The composition and hardness above are measurable; this paragraph is folklore, and worth reading as such.
Questions
What is Moonstone made of?
Potassium aluminium silicate (KAlSi₃O₈) — feldspar, crystallising in the monoclinic system.
Which month is Moonstone the birthstone for?
June.
Where does Moonstone come from?
Sri Lanka, India, Madagascar, Myanmar.
How do I clean Moonstone?
Soapy water and a soft cloth. Never ultrasonic — feldspar cleaves easily and vibration can split it.
How can I tell if Moonstone is real?
Opalite and milky glass are the usual substitutes. Real moonstone shows adularescence that moves as you tilt it; glass shows a static sheen that stays put.
Can I wear it every day?
At 6–6.5 on the Mohs scale, not in a ring. Keep it to pieces that take fewer knocks.