types of Rocks
Igneous rocks are created from lava or magma that has cooled,they may be sparkly,glassy,or lightweight because of a lot of air holes.
You can identify andesite by the general color range,bluish-grey or grey. Diorite has a speckled black and white color,with an occasional pink or blue shade. Pyroxenite has cleavage that intersects at 87° and 93°. Pumice has a lot of air holes,so it looks like a sponge. Dunite is primarily green,and it is coarse grained.
Metamorphic rocks are harder than igneous or sedimentary,they often have striped bands,and are often pebbly because other rocks were flattened into them.
Granullite is black with speckles of red garnet. Talc can be white, beige, gray, yellow, brown, pink, purple, blue, green,it will flake if you scratch it with your fingernail. Chlorite is light to dark green, grayish-green, black,white, yellow, brown, pink and purple. The streak is white. Hornfels is a fine grained rock composed mostly of quartz. Serpentine is white, yellow, green, gray, brown, black, purple,green and yellow. It has a white streak.
Sandstone is generally tan or yellow and it has a course grain. Breccia has angled pebbles,and it is course grained. Halite tastes like salt,and has a white streak. Limestone can be white,gray,or right in the middle,it may occasionally have fossils. Chert can be black,brown,red,or yellow,it is also referred to as flint for darker shades.