Quartz with fine inclusions of dumortierite—a blue mineral dispersed throughout the stone. When light enters, these inclusions produce a faint shimmer from within. The effect is called aventurescence.

"Aventura""—Italian for ""chance."" In eighteenth-century Venice, a glassmaker accidentally dropped copper filings into molten glass, creating a sparkling material by mistake. The natural stone took its name from a man-made accident.

Found in India, Brazil, and Russia, less commonly than its green counterpart. Blue mineral hidden within blue quartz—layers of the same colour family, producing a light with quiet depth.