Porphyry, an igneous granite that forms when magma is exposed to air through fissures in the Earth's crust, is the latest darling of landscape designers. Essentially a fast-cooled magma, porphyry is ...

I live in central New Hampshire, aka the Granite State. They don’t call it that for nothing. My own house sits directly on top of one of the enormous granite plutons, the Meredith Porphyritic Granite.