many various gemstones close up

agat amazonite amethyst aventurine carnelian citrine close collection color colored decorative different gem gemmological gemmology gemological gemology gems gemstone geological geology handful heap howlite jasper jewelry labradorite lapis lazuli lot many mineral mineralogy multi multicolor multicolored natural obsidian ornamental pebble pile polished precious quartz rhodonite rock semi semiprecious stone surface tumbled various white