It’s a low grade metamorphic marble or also or also called crystalline limestone. The colour varies from white to cream, hence the name “Ecru”. It was formed from old reefs, so there are abundant fossils visible in these tiles, revealing their Mesozoic age. The material is very homogeneous, and therefore very well suited for (high rise) cladding and large flooring areas. It polishes well, although in today’s applications, the honed surface is most popular. Calcite re-crystallization has filled all open pore spaces, so there is both a very low porosity and permeability present in this material, which makes it resistant against fungi growth and acidity penetrating into the stone. As there is free iron, manganese nor magnesium present in the rock, it can be safely used in the full sun, humid climates without becoming yellow/brown after some time. It is commonly used for water features and it’s also suitable for swimming pools.