Granite is an intrusive igneous rock which is widely distributed throughout Earth’s crust at a range of depths up to 31 mi (50 km). Granite’s characteristic grainy structure and strength is the result of many individual crystalline structures which form tightly together as magma slowly cools within large, deeply buried rock bodies known as plutons. True granite contains 20-60% quartz as well as both plagioclase and alkali feldspars of which the former may not exceed general balance. Other minerals such as hornblende and biotite may also occur in granite, accounting for its variety of appearances (Alden 2004). Commercially, the term ‘granite’ includes a range of other types of non-granite dimension stone including any feldspathic crystalline rocks or other igneous or metamorphic rocks which possess qualities similar to granite’s grainy, interlocking texture. Many variations of granite appear on the commercial market with white, gray, pink, and red being the most common primary colors. Greens and browns are also available as well as darker grays and black. The production of commercial granite typically exceeds production of all other stone types, barring limestone which has surpassed granite production in recent years (Dolley 2003, 2004, 2005, 2006, 2007a, 2008, 2009). The U.S. Geological Survey estimates that granite is currently quarried in at least 17 U.S. states with Georgia, Massachusetts, New Hampshire, Vermont, and Wisconsin leading production (Dolley 2007b). Its primary uses include curbing, monumental rough and dressed stone, as well as an array of applications throughout the building industry; this study focuses on dimension granite.
The Plain and Simple Facts About Radon and Radiation
If you are confused about the difference between radon and radiation, this article should set the record straight.
Radon is a naturally occurring radioactive gas found all around us. The U.S. EPA says the primary source of radon in a home is the soil surrounding. Most radon dissipates in the atmosphere, but sometimes if can seep into a home’s basement. In high enough concentrations, prolonged exposure can lead to lung cancer. Radon venting equipment can solve the problem.
There is not a shred of scientific evidence that suggests granite countertops in the home contribute to higher radon concentration in the home.
Radiation also occurs naturally and it’s primary source is the sun. Your exposure to sun-based radiation is based largely on where you live. For instance, if you live in Denver, the mile-high city, you are closer to the sun than, say, if you lived in Des Moines, which is not nearly has high.
There are a lot of other things that can cause radiation in the home. including cement blocks, TV sets and smoke detectors — and even Brazil nuts, bananas and potatoes. The fact is, they are no more harmful than granite countertops.
-Marble Institute of America (MIA) and Building Stone Institute
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