Types of Marble4 min read

What is marble?

Marble is a metamorphic rock formed when limestone is subjected to heat and pressure deep in the earth’s crust, recrystallising its calcite into an interlocking mosaic of crystals. That recrystallisation is what gives marble its density, its soft translucency and its ability to take a high polish, and it is why marble has been the material of choice for sculpture and prestige architecture for millennia.

Commercial marble and geological marble are not the same thing

This is the distinction that catches project teams out, and it is worth understanding before you specify anything.

In geology, marble is metamorphosed limestone. In the stone trade, ‘marble’ means something considerably broader. ASTM C119, the standard terminology for dimension stone, defines commercial marble as a crystalline rock capable of taking a polish, composed of one or more of the minerals calcite, dolomite or serpentine. Recrystallised limestone, compact microcrystalline limestone and travertine that are capable of taking a polish also fall within the commercial marble category, and may be sold as either limestone or marble.

In other words, a stone can be sold to you quite legitimately as marble without being marble in the geological sense at all.

Why the distinction matters

It matters because the specification and the testing follow the geology, not the sales name. Each material sits under a different ASTM specification:

Material	ASTM specification	Often sold as
Marble	ASTM C503	Marble
Limestone	ASTM C568	Frequently marketed as marble when it polishes
Serpentine	ASTM C1526	Almost always sold as ‘green marble’
Travertine	ASTM C1527	Sometimes sold as marble

A stone specified as marble but supplied as a polished limestone will be tested against the wrong criteria, and may behave quite differently in service, particularly on an exterior facade where absorption and flexural strength govern performance. We have seen exactly this on projects we were called in to inspect: material arriving on site, sometimes already being installed, that was not the material specified.

Our own portfolio shows the distinction in practice. The U.S. Embassy in Kingston, Jamaica used 1,500 square metres of Crema Marfil, a stone very widely sold as marble but correctly specified and handled as a limestone.

Common types of marble

Most of the world’s best known marbles come from a handful of deposits. The table below covers those most often specified in architecture.

Marble	Origin	Character
Carrara	Carrara, Tuscany, Italy	White to blue-grey with soft, feathery grey veining. The most widely used white marble in the world.
Calacatta	Carrara region, Italy	A whiter background with bolder, more dramatic veining. Considerably rarer than Carrara, and priced accordingly.
Statuario	Carrara region, Italy	Bright white with striking grey veining. Historically the sculptor’s marble.
Estremoz	Estremoz, Alentejo, Portugal	White to soft pink, fine grained, and translucent enough to be lit from behind.
Thassos	Thassos, Greece	Exceptionally white, close to pure calcite, with almost no veining.
Nero Marquina	Basque Country, Spain	Deep black with sharp white veining.

Marbles we have worked with

At the Ronald O. Perelman Performing Arts Center in New York, 6,960 square metres of Estremoz marble were quarried in Portugal, sawn to 15mm, calibrated to 12mm and laminated between panes of glass to produce a translucent facade of 4,896 panels. It is a good illustration of a point worth making about marble: its reputation for being difficult to handle has seen it lose ground to cheaper alternatives on large projects, but modern engineering, in this case lamination and glazing, can transform its resilience and open up uses that were not previously possible.

For the New Palace of Justice in Kuwait, the specification includes Statuario Altissimo and Bianco Altissimo alongside Classic Roman Travertine.

Specifying marble with confidence

If you are specifying marble on a project of any scale, three questions are worth asking early. Is the stone you have been offered actually the material named in the specification? Which ASTM standard should it be tested against, and has it been? And can the quarry supply the quantity you need in a consistent range for the whole package?

Those questions are best answered at the quarry, not on site. Read about our independent natural stone inspection service, or get in touch to discuss a project.

Further Reading…

Read our guide to dimension stone, and our summary of the ASTM standards for natural stone.

Read about stone facades in architecture.