A museum-quality specimen of grape agate made of aggregates of spherical purple quartz with green-hued crystals on one side, originating from West Java. Grape agate is the common name for a botryoidal variety of quartz that naturally occurs as small spheres of purple and sometimes blue-green, and often resembles clusters of the fruit. Grape agate, somewhat misnamed as it is not a true agate due to a lack of banding, is also frequently described as a form of chalcedony, but is more accurately described as a form of microcrystalline quartz. This specimen measures approximately 13" x 5" x 12.5" tall and has a weight of 15 pounds, 4.6 ounces.