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WELCOME TO ELBERTON GRANITE ASSOCIATION:

   

Granite Facts

What is granite?

Granite is a tough, durable rock composed primarily of three different minerals. These minerals are easy to see due to their different colors. The white mineral grains found in granite are feldspar. It is the most abundant mineral found in granite. The light gray, glass-like grains are quartz, and the black, flake-like grains are biotite or black mica.

Granite and marble. How are they different?

Marble is simply limestone that has been compressed and/or heated deep within the earth's crust. Unlike granite, marble was never molten rock, but it may have been heated and squeezed enough for the limestone grains to bend and flow. Marble is also made up of only one mineral -- calcite -- a relatively soft mineral with a hardness of "3". Calcite is a common mineral -- all limestones and nearly all seashells are made of it, but it does not occur in granite. Because marble is made entirely of calcite, it is much softer than granite.

How was Elberton granite formed?

Elberton granite began 325 million years ago as a large, hot (1300 degrees to 1400 degrees Farenheit) mass of magma or molten rock. This magma originated when some of the earth's crust melted -- probably at a depth of about 11-12 miles. The magma rose upward and came to rest about nine miles beneath Elberton. There it cooled very slowly -- taking more than a million years -- and solidified into granite. That was more than 300 million years ago.

Since then, the granite has been pushed upward, and the land above it has been removed by erosion. The result is a granite deposit that lies just beneath the earth's surface where it can be easily, safely and economically quarried.

How much granite is in the Elberton area?


EGA QUALITY REPORT:

The Stone Industry recognizes granite as one of the hardest of all natural stones. Elberton Granite has been a stone of choice for public and private memorials as well as countless commercial uses for almost 100 years. In 1969 the Elberton Granite Association contracted with the Georgia Institute of Technology (Georgia Tech) to run a blind test on samples of Elberton Granite as well as a few samples from other areas. The tests were done to determine the physical and mineral properties of Elberton Granite and how it compares with other granites. The results of these tests have been shared with the industry for decades.

Read more about the EGA Quality Report.

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