2027 Forecast

White to gray with blue sheen

Moonstone birthstone

Moonstone, the birthstone for June, is potassium aluminum silicate (KAlSi₃O₈) — feldspar, white to gray with blue sheen, rated 6–6.5 on the Mohs scale. Traditionally, it is linked to intuition, cycles and new beginnings — attributed, not demonstrated.

Mohs hardness
6–6.5 scratches window glass
Crystal system
Monoclinic KAlSi₃O₈
Main sources today
Sri Lanka also India, Madagascar

Stones described in similar terms: labradorite, rose quartz, obsidian, amber, tiger's eye and fluorite.

Listed under: June birthstone and Cancer birthstones.

Linked in crystal practice with the sacral chakra and third eye chakra.

Further along the same lines: sardonyx, citrine and aquamarine.

Moonstone Birthstone: The June Stone and Its Meaning

Is Moonstone a birthstone?

Yes. Moonstone is the modern birthstone for June.

By zodiac sign it belongs to Cancer.

Properties

Composition Potassium aluminum silicate (KAlSi₃O₈) — feldspar
Hardness (Mohs) 6–6.5
Crystal system Monoclinic
Color White to gray 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

Popular in Art Nouveau jewelry around 1900; the often-repeated story that Romans thought it was solidified moonlight is lore rather than a documented Roman belief.

Buying

Buying Moonstone: fakes, value and treatments

What it is confused with

Milky glass and "opalite" imitate it; "rainbow moonstone" is a trade name for white labradorite rather than true moonstone.

What decides the price

A transparent, colorless body with a strong blue sheen that floats across the stone is most valuable. It is cut as a cabochon so the sheen shows.

Where it is used

Popular in Art Nouveau jewelry, including pieces by René Lalique.

A less familiar fact

Florida made moonstone its state gemstone in 1970 to mark the Moon landings, though the stone is not found there.

Practical

Caring for Moonstone

How to clean it

Soapy water and a soft cloth. Never ultrasonic — feldspar cleaves easily and vibration can split it.

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.

How to store stones so they do not scratch each other →

How hard is Moonstone?

Moonstone is a feldspar and cleaves easily, so a hard knock can split it along a plane long before scratches show. A protective setting matters more than the hardness number. Labradorite and Pyrite share its place on our scale. Among the stones in this reference, the next softer is Opal (5.5–6.5) and the next harder Tanzanite (6–7).

Moonstone on the Mohs hardness scale
Moonstone on the Mohs hardness scaleMohs scale from talc (1) to diamond (10), with the 43 stones of our reference as dots and Moonstone (6–6.5) marked as a bar.Moonstone: Mohs 6–6.5Moonstone 6–6.5Garnet: Mohs 6.5–7.5Amethyst: Mohs 7Citrine: Mohs 7Rose Quartz: Mohs 7Clear Quartz: Mohs 7Smoky Quartz: Mohs 7Aquamarine: Mohs 7.5–8Emerald: Mohs 7.5–8Bloodstone: Mohs 6.5–7Peridot: Mohs 6.5–7Sardonyx: Mohs 6.5–7Zircon: Mohs 6–7.5Carnelian: Mohs 6.5–7Onyx: Mohs 6.5–7Agate: Mohs 6.5–7Tiger's Eye: Mohs 6.5–7Aventurine: Mohs 6.5–7Diamond: Mohs 10Pearl: Mohs 2.5–4.5Alexandrite: Mohs 8.5Moonstone: Mohs 6–6.5Labradorite: Mohs 6–6.5Pyrite: Mohs 6–6.5Ruby: Mohs 9Sapphire: Mohs 9Spinel: Mohs 8Topaz: Mohs 8Opal: Mohs 5.5–6.5Rhodonite: Mohs 5.5–6.5Tourmaline: Mohs 7–7.5Turquoise: Mohs 5–6Lapis Lazuli: Mohs 5–6Hematite: Mohs 5–6Tanzanite: Mohs 6–7Jade: Mohs 6–7Obsidian: Mohs 5–5.5Malachite: Mohs 3.5–4Amber: Mohs 2–2.5Selenite: Mohs 2Fluorite: Mohs 4Sodalite: Mohs 5.5–6Kyanite: Mohs 4.5–7Lepidolite: Mohs 2.5–31Talc2Gypsum3Calcite4Fluorite5Apatite6Orthoclase7Quartz8Topaz9Corundum10Diamondfingernail 2.5window glass 5.5household dust (quartz) 7Source: Mohs scale minerals · ranges from our 43-stone referenceastrohot.com
Moonstone on the Mohs hardness scaleMohs scale from talc (1) to diamond (10), with the 43 stones of our reference as dots and Moonstone (6–6.5) marked as a bar.Moonstone: Mohs 6–6.5Moonstone 6–6.51Talc2Gypsum3Calcite4Fluorite5Apatite6Orthoclase7Quartz8Topaz9Corundum10Diamondfingernail 2.5glass 5.5dust 7Source: Mohs scale minerals · ranges from our 43-stone referenceastrohot.com

Moonstone, at 6–6.5, is harder than 14 of the other 42 stones here and softer than 26.

Traditional associations

Moonstone is traditionally linked to intuition, cycles and new beginnings. Chakra in crystal practice: Sacral, Third Eye. Element: Water.

What is measured here and what is tradition →

Questions about Moonstone

What is Moonstone made of?

Potassium aluminum silicate (KAlSi₃O₈) — feldspar, crystallizing in the monoclinic system.

Which month is Moonstone the birthstone for?

June.

Where does Moonstone come from?

Sri Lanka, India, Madagascar, Myanmar.

Can Moonstone be worn every day?

With care. At 6–6.5 on the Mohs scale it can be worn often, but watch out for hard knocks, which can split it along a cleavage plane.

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Cite this page

AstroHot. “Moonstone Birthstone: The June Stone and Its Meaning.” Accessed October 28, 2026. https://astrohot.com/crystals/gemstones/moonstone/

For Wikipedia {{cite web |title=Moonstone Birthstone: The June Stone and Its Meaning |url=https://astrohot.com/crystals/gemstones/moonstone/ |website=AstroHot |access-date=2026-10-28}}