Oak apple due to the superficial resemblance and the preponderance of the oak marble gall in the wild. Other galls found on oak trees include the oak artichoke gall and the acorn cup gall, but each of these has its own distinctive form. Some common oak-apple-forming species are the "Biorhiza pallida" gall wasp in Europe, "Amphibolips confluenta" in eastern North America, and "Atrusca bella" in western North America. Oak apples may be brownish, yellowish, greenish, pinkish, or reddish. Oak galls have been used in the production of ink since at least the time of the Roman Empire. From the Middle Ages to
Royal Oak Mines million on revenues of US$187 million for fiscal 1996. Its Hopebrook and Colomac mines were closed in 1997. Low gold prices of 1997-1998 caused Royal Oak to go bankrupt in April 1999, and its mining assets were liquidated. Royal Oak Mines' operations at the Giant Mine in Yellowknife became infamous in Canada during the 1990s as the site of a protracted and violent industrial relations dispute that lasted eighteen months. The declining price of gold led to Witte demanding pay cuts, which the Canadian Association of Smelter and Allied Workers union (CASAW) Local 4 refused, arguing that the company was