What is Granite?
Granite is a light-colored igneous rock with grains large enough to be visible with the unaided eye. It forms from the slow crystallization of magma below Earth’s surface. Granite is composed mainly of quartz and feldspar with minor amounts of mica, amphiboles, and other minerals. This mineral composition usually gives granite a red, pink, gray, or white color with dark mineral grains visible throughout the rock. The word "granite" comes from the Latin granum, a grain, in reference to the coarse-grained structure. Granite is a plutonic rock in which quartz makes up between 10 and 50 percent of the felsic components and alkali feldspar accounts for 65 to 90 percent of the total feldspar content. Applying this definition requires the mineral identification and quantification abilities of a competent geologist.
The Best-Known Igneous Rock
Granite is the best-known igneous rock. Many people recognize granite because it is the most common igneous rock found at Earth's surface and because granite is used to make many objects that we encounter in daily life. These include countertops, floor tiles, paving stone, curbing, stair treads, building veneer, and cemetery monuments. Granite is used all around us - especially if you live in a city.
EarthCache Task
At the given coordinates you will find a Commemorative Rock. In order to prove your visit and claim the find, I ask that you email me the answers to the below-listed questions. Please take a photo of yourself/selves with said rock.
Questions:
1) Look closely at the rock, what is the approximate percentage (to the nearest 10%) of quartz in this granite rock?
2) How tall is the rock?
Happy Caching!
References
http://geology.com/rocks/granite.shtml
http://en.wikipedia.org/wiki/Granite
Please note : You are welcome to log this Earthcache after sending your answers to me. If no answers are received, your log will be deleted. Please be mindful of your logs to ensure there are no spoiler images/answers for the questions above, spoilers will also be removed.