Why does obsidian have no crystals? Why is radiometric dating not accurate for sedimentary rocks? Why are alloys useful? Why are chemical radicals important in mineralogy? Why is glass not a mineral? How does rock type contribute to geological research?
Why is ice the solid form of water? Why do the crystals in gneiss line up in bands? Why is naphthalene insoluble in water? Why does carbon tetrachloride not dissolve in water? Why does obsidian have no crystals? Why is the freezing of water called a physical change?
It is what’s called a volcanic plug, and is made out of a similar mineral composition as the adjacent dacite flows (but with a bit less silica). However, while dacite and andesite are both technically extrusive rocks, the andesite of Cathedral Rock rose up into a volcanic vent and ...
Why is the Earth's core hot? Why does obsidian contain few or no mineral grains? Why do extrusive rocks have air pockets? Why are crystalline solids brittle? Why do minerals have geometric shapes? Why are fossils never found in igneous rocks?