Sanidine

Sanidine is a high-temperature version of the mineral potassium feldspar, commonly found in volcanic rocks. It forms when magma cools rapidly, locking in its crystal structure. Sanidine has a clear, glassy appearance and common in rocks like rhyolite and tuff. Its structure is slightly different from other feldspars, making it useful for geologists to determine the cooling history and age of volcanic rocks through radioactive dating. Overall, sanidine helps scientists understand volcanic activity and Earth's geological past.