Information and history of jade plus a gallery of jade used in antique and vintage brooches. Nephrite and jadeite were used from prehistoric periods for hardstone carving. Jadeite has about the same hardness as quartz. Nephrite is slightly softer but tougher (more resistant to breakage) than jadeite. It was not until the 19th century that a French mineralogist, Alexis Damour (1808-1902), determined that “jade” was in fact two different minerals. Reference: Wikipedia