detail of semiprecious gemstone of citrine

south america brazil rio grande gramado texture abstract background rock mineralogy mineral ore deposit dig lode vein extraction underground subsurface mining geological gemology materials valuable november birthstone lapidary geode crystal druse lustre luster shiny amethystgrotto treasure vitreous gem stone semiprecious gemstone quartz amethyst detail jewel polished orange smoky heattreated amethysts citrine