Okay, I’m sorry for the pun. Please, don’t leave.
My friends, this is a post about granite. In fact, this post may be so epic, I’ll have to split it into two posts, or maybe even a trilogy of posts. Peter Jackson, call your office.
There is a lot to discuss about natural stone used for countertops. We can talk about geology (of course), material care and maintenaince, and the longest part of all, my selection process. I also have two shout outs to make in the course of these posts. The first is to my amazing colleagues, Robin and Sonia, who helped me so much in this endeavor. Evidence of their help will be visible in the pictures.
So let’s start with granite. As you all know– at least those of you who are actually geologists — what is called granite in the counter biz is not really granite in the geoscience world. Granite is specifically a type of igneous rock with distinguishable mineral crystals, composed mostly of quartz and feldspar with other minerals like biotite and hornblende.
I think this graph makes it clear:
Ha Ha. Maybe some pretty pictures will explain it better. After the jump:
I got most of these pictures from http://geology.com/rocks/granite.shtml. I’ve realized they explain all about granite in the geoworld and the commercial world much better than I do, so go look. This is good too http://www.findstone.com/article/basic-knowledge-stones.
To illustrate: This is granite
And so is this
But this is not.
(See my door and paint samples? Thanks Robin.)
Neither is this. But it’s the stone I ended up picking (I’m foreshadowing the end of the trilogy.)
River White “Granite”: this is likely a gneissic, formerly sedimentary rock. You can clearly see quartz grains, but the grey streaks and garnets point to the rock being subjected to high temperature and pressure metamorphism (Thanks Sonia)