Natural quartz mineral is a naturally occurring mineral composed of silicon and oxygen atoms. It is a hard and durable material that is often used in jewelry and decorative items. Glass, on the other hand, is a man-made material composed of sand, soda ash, and limestone. While both materials can be transparent and have similar appearances, natural quartz is a mineral formed in the Earth's crust, while glass is a manufactured material. **

Yes, coins can be used as guitar picks. Many guitarists use coins as an alternative to traditional guitar picks, as they can produce a unique sound and offer a different feel when playing. However, using coins as guitar picks can also cause more wear and tear on the strings and may not be as flexible as traditional picks, so it's important to consider the potential impact on the guitar and strings before using coins as picks. **