Soft, occurs in 'books', splits into thin sheets. can be silvery-white or black.
A hard metamorphic rock made of solid quartz, light to dark gray or pink.
Dark-coloured igneous rock, may be full of vesicles.
Volcanic rock rich in silica, fine-grained, can be light gray, white, tan, pink.
Very fine-grained sedimentary rock, feels smooth and breaks into thin layers. May contain preserved leaf, insect or fish fossils.
Jet-black, elongated crystals, no cleavage. found in granite and especially in pegmatite.
A dark green to black metamorphic rock containing hornblende. was basalt lava before being metamorphosed.
Sedimentary rock, made of calcite, usually gray, fizzes in acid or vinegar.
A hard, pistaschio-green mineral, often seen as thin veins in granite.
Sedimentary rock, made of sand grains and feels like sandpaper. can be red, brown, yellow, white or gray. may contain fossils.
A very coarse-grained type of granite, with large crystals or quartz, feldspar, mica, and sometimes beryl, topaz or tourmaline.