required in the formation of jasper. Jasper can be modified by the diffusion of minerals along discontinuities providing the appearance of vegetative growth, i.e., dendritic. The original materials are often fractured and/or distorted, after deposition, into diverse patterns, which are later filled in with other colorful minerals. Weathering, with time, will create intensely colored superficial rinds. The classification and naming of jasper varieties presents a challenge. Terms attributed to various well-defined materials includes the geographic locality where it is found, sometimes quite restricted such as "Bruneau" (a canyon) and "Lahontan" (a lake), rivers and even individual mountains; many are fanciful, such as "forest fire" or "rainbow", while others are descriptive, such as "autumn" or "porcelain". A few are designated by the place of origin such as a brown Egyptian or red African. Banded iron formations Jasper is the main component in the silica-rich parts of banded iron formations (BIFs) which indicate low, but present, amounts of dissolved oxygen in the water such as during the Great Oxidation Event or snowball earths. The red bands, typically more competent than the hematite layers surrounding it, are made of microcrystalline red chert, also called jasper. Picture jaspers Picture jaspers exhibit combinations of patterns resulting in what appear to be scenes or images, when seen on a cut section. Such patterns include banding from flow or depositional patterns (from water or wind), as well as dendritic or color variations. Diffusion from a center produces a distinctive orbicular appearance, i.e., leopard skin jasper or linear banding from a fracture as seen in liesegang jasper. Healed, fragmented rock produces brecciated (broken) jasper. While these "picture jaspers" can be found all over the world, specific colors or patterns are unique to the geographic region from which they originate. One source of the stone is Indonesia, especially in Purbalingga district. From the US is Oregon's Biggs jasper and Idaho's Bruneau jasper from the Bruneau River canyon are particularly fine examples. Other examples can be seen at Ynys Llanddwyn in Wales. A remarkable, pale, blue-green jasper, with patterns somewhat resembling those of malachite, occurs in a deposit at Ettutkan Mountain, Staryi Sibay, Bashkortostan, Russia. (The town of Sibay, in the far south of the Ural Mountains, near the border with Kazakhstan, is noted for its colossal, open-cast copper mine.) Basanite and other types of touchstone Basanite is a deep velvety-black variety of amorphous quartz, of a slightly tougher and