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A stone guide

Marble

Michelangelo's David and most 'onyx' gift-shop bowls share the same mineral, calcite, polished two very different ways.
Metamorphic (recrystallized carbonate)PakistanSee treatment disclosure

Marble is metamorphic (recrystallized carbonate), (CaCO₃ dominant). In the hand, it rates 3 to 4 (aggregate) on the Mohs scale, and it runs white and gray-veined. Sugary-sparkly recrystallized stone, soft to a knife, fizzing in vinegar, the glittery cousin of dull limestone. Metamorphosed limestone; notable: Carrara (Italy), Greece, Vermont (USA), Pakistan.

Family
Metamorphic (recrystallized carbonate)
Mohs
3 to 4 (aggregate)
Luster
Sugary vitreous
Gravity
2.6 to 2.8
Light
Opaque; translucent in thin slabs
What it is

The geology.

Marble carries the formula (CaCO₃ dominant). It belongs to the, system. Its listing category is metamorphic (recrystallized carbonate).

It sits at 3 to 4 (aggregate) on the Mohs scale. The surface reads sugary vitreous. Light behaviour is opaque; translucent in thin slabs. Specific gravity runs 2.6 to 2.8. The streak is white. It breaks with granular, sugary fracture.

Sugary-sparkly recrystallized stone, soft to a knife, fizzing in vinegar, the glittery cousin of dull limestone.

It turns up mostly as carvings, spheres, bookends, decor or 'onyx' bowls (banded marble).

Where it comes from

The origins.

Metamorphosed limestone; notable: Carrara (Italy), Greece, Vermont (USA), Pakistan.

On value, the database notes: common and affordable.

What people work with it for

Traditional associations.

In energy work traditions, associated with clarity of purpose and serenity.

This is lore, and we label it as lore. The measurable facts are further up the page.

What to look for

Spotting the real thing.

Sugary-sparkly recrystallized stone, soft to a knife, fizzing in vinegar, the glittery cousin of dull limestone.

Frequently sold as 'onyx' when banded, a centuries-old trade habit; vinegar settles it.

Looks like How to tell them apart
Quartzite Quartzite looks similar but scratches glass and never fizzes
White howlite Howlite shows gray web veins and no sugary sparkle
'Onyx' carvings Banded translucent 'onyx' bowls are calcite/aragonite marble, they fizz, true onyx (chalcedony) doesn't
Check it yourself

At-home tests.

A loupe and a window seat settle most questions about marble. No workshop required.

Test What you should see
Acid check Fizzes with vinegar
Scratch check Knife scratches it easily
By eye Sugary crystal sparkle on broken faces

If these checks leave you unsure, that is what appraisers are for. Do not file, heat or soak a piece to find out.

How to live with it

Care & handling.

At 3 to 4 (aggregate) on the Mohs scale this is a soft material. Keep it as a display piece, store it apart from harder stones, and skip daily-wear settings.

It breaks with granular, sugary fracture, which is worth knowing before you set it or drop it.

Most damage happens during cleaning, not wearing. Avoid steamers, ultrasonic tanks and anything from under the sink.

For the serious reader

A deeper look.

Extended detail on composition, sourcing, authentication and market value.

The physical record

The formula on record is (CaCO₃ dominant). Crystal system:,. Specific gravity: 2.6 to 2.8. Streak: White. Cleavage and fracture: Granular, sugary fracture.

How it reaches the market

Metamorphosed limestone; notable: Carrara (Italy), Greece, Vermont (USA), Pakistan.

What it gets confused with

Quartzite: Quartzite looks similar but scratches glass and never fizzes. White howlite: Howlite shows gray web veins and no sugary sparkle. 'Onyx' carvings: Banded translucent 'onyx' bowls are calcite/aragonite marble, they fizz, true onyx (chalcedony) doesn't.

What it is worth

Common and affordable.

Where buyers get caught

Frequently sold as 'onyx' when banded, a centuries-old trade habit; vinegar settles it.

One more thing

Michelangelo's David and most 'onyx' gift-shop bowls share the same mineral, calcite, polished two very different ways.

From the Beyond Bohemian library

An education-first guide.

There is nothing to buy on this page. Marble is not part of our catalogue, and the guide is here anyway because somebody searching the name deserves a straight answer.

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