Rock & Gem
All Things Pennsylvania
Inside the Wertz Gallery, the Cut & Polished Pennsylvania Gems & Minerals exhibit features gems, jewelry, gemstones, cabochons, polished spheres and carvings made from minerals unearthed in the state of Pennsylvania. Among them, is a type of hard coal known as jet, and williamsite (the highly translucent gem variety of antigorite or serpentine) found along the state line with Maryland in Lancaster County’s Chromite District. Williamsite was named after mineralogist and geologist Lewis White Williams, of West Chester, Pennsylvania. Several faceted gemstones of quartz, amethyst, aquamarine and titanite are on exhibit along with cabochons of malachite, blue quartz, sunstone, amazonite, a polished sphere of copper and quartz, and blue quartz. Two other cabochon pieces on exhibit — epidote and cuprite in silicified rhyolite — are self-collected and cut and polished by the famous John Sinkankas, the 1988 Carnegie Mineralogical Award winner.