The Earth is a stone-making factory. Although most of the granites, marbles, travertines and limestones we sell are very old, it’s important to realize that the processes that created them are still going on today.

The Earth’s surface consists of huge plates which float on the molten mantle underneath. The Pacific plate lies underneath the Pacific Ocean and carries not only the ocean itself, but all the Pacific Islands including the Hawaiian chain. The North American plate carries not just North America, but also half the Atlantic Ocean. The other half of the Atlantic is part of the Eurasian and African plates. At the middle of the Atlantic Ocean is the Mid-Atlantic Ridge, which is a "spreading center."

When these plates collide or separate, geology happens. Millions of years ago, the plates that now carry Africa, Europe, Asia, and North and South America had all combined to form one huge super continent. When they drifted apart, the Atlantic Ocean was born, and it is still widening at the rate of two-to-four centimeters a year. At the same time, the Pacific Ocean is slowly narrowing, dipping under North America and Asia, as the Atlantic and Pacific Oceans move towards each other.

The Earth is a constantly changing, living system. Italy, pushed by Africa, is still in the process of colliding with Europe, a collision that is raising the Alps. India’s collision with Asia is still pushing up the Himalayas. Closer to home, the Sierra are still coming up, pushed by the Pacific plate, causing earthquakes along the Nevada front. And underneath it all, stone is forming, metamorphosing, and remelting into the molten mantle. The stones we sell are snapshots of moments in time in the Earth’s history.

As earth’s plates continue their ongoing collisions, ancient sea bottoms are often thrust miles into the air. The summit of Mt. Everest is marine limestone, pushed more than seven miles into the air – so far – by the collision of India with the Asian continent.

Granite is formed deep beneath the earth’s crust, and rises from the molten magma, forming at temperatures in the thousands of degrees. Many of the oldest stones on earth come from the ancient cores of the continents, which probably formed and hardened as the earth cooled over four billion years ago. Dakota Mahogany granite from North America and Juperanas granite, from South America, Africa, and India, are among these truly ancient stones. Other, younger granites have formed under rising mountain ranges like the Sierra, welling up under the local "country" rock as plutons or domes. Sierra White and Academy Black came up under the future Sierra Nevada as the dinosaurs were dying out, 140 million years ago. New granites are forming even today, far beneath the Alps and the Himalayas, which are still rising.

Limestone has been used as exterior building cladding since time immemorial. Though most of it is gone, looted to build other structures, the Great Pyramids in Egypt were originally clad in smooth, perhaps even polished, limestone, as are many of the great cathedrals of Europe, such as Notre Dame in Paris. Sadly, many of these have fallen victim to a more modern menace, the acids found in polluted air, which have actually dissolved the surfaces and deteriorated the stone.

Though limestone is primarily calcareous – composed of the mineral compound calcium carbonate – other minerals present in the sediments produce various colors. Many of the limestones we sell were formed during the Jurassic period, which makes them 140-190 million years old. Heat and pressure have a dramatic effect on the density and appearance of limestones. Beaumaniére and Gascogne, for example, are less hard than Rojo Alicante, New Pink, and Crema Marfil. Those latter three stones will take a high polish, and are usually classified commercially as marble.

Limestone is still being born on ocean floors. If you’ve watched any of the Jacques Cousteau specials, or the specials on exploring the Titanic’s wreckage, you saw the constant downward flow of particles and sediments in the process of forming layers that will someday lithify as limestone. As the Titanic continues to deteriorate and rust away, it will contribute iron and other minerals to that constant deposit, and give that vein of future limestone a large burst of color, primarily reddish or yellowish. All stone is not alike. All stone suppliers are not alike. Click here for the Intertile Difference.

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