Porphyry, any igneous rock consisting of large crystals in a mass of much smaller crystals. The large and small crystals usually are of different minerals; the rock is generally named according to its major component (for example: granite porphyry). When cut and polished, porphyry has a beautiful pattern and contrast of colors. It is used for tombstones and ornamental panels.
He is famous for a phrase he never said, for wearing turtlenecks and for hosting the original 'Cosmos' TV series. As enthusiastic about the stars as he was about marijuana, Carl Sagan led a very surprising life. Here are 10 cool facts.
One was a celebrated author, the other a famed physicist. What the two shared was a public exposure of their religious beliefs. Big E had an on-again, off-again relationship with God, while C.S. was an avowed atheist during his early years.