Like so many other minerals, aventurine is, yes, a kind of quartz. It’s normally green, and what makes it so “aventurous,” so to speak, is that it has flakes of mica in it that sparkle. In this case, the kind of mica is called “fuchsite” and is green as well, with the green caused by the element chromium. Aventurine can also be other colors, such as orange or brown, and those two colors are caused by iron minerals such as hematite and goethite. Aventurine got its name in an unusual way. When it was discovered, there was already a kind of glass made in Murano, Italy, that had sparkly flakes of metal in it and was called avventurina. The story goes that a glassmaker dropped some flakes of copper into some molten glass by accident, or “a ventura” in Italian, and the results were pretty nice, so they started doing the same thing on purpose and selling their sparkly glass. When a similar-looking mineral came along, they named it after the glass.