Question: What precious metal does Outpost Island Mine and Hedley Mascot Mine have in common?

Context articles: Hedley Mascot Mine
Kanichee Mine
Hedley, British Columbia
Svenska Bergsbruk
Fineness
Mercury silvering
Methods of coin debasement
Outpost Island Mine
Precious metal (disambiguation)
Base metal

The Hedley Mascot Mine was a gold mine in Hedley, British Columbia, Canada.
 Gold was first discovered in the Nickel Plate Mountain area in 1897 and several small mines were developed over the years.
 The Hedley Mascot Mine operated between 1936 and 1949 and was one of the most unusual mining operations in the world, being built entirely on the side of a mountain, 5,000 feet above the town of Hedley or seven thousand feet above sea level.
 In the 1990s, the British Columbia government was going to burn the site down because it posed a safety risk, but the Minister of Tourism at the time intervened and, in 1995, steps were taken to preserve the site as a Provincial Heritage resource.
The Kanichee Mine, also less commonly known as the Ajax Mine, is an abandoned base metal and precious metal mine, located in the Temagami region of northeastern Ontario, Canada.
 It is near the small unincorporated community of Temagami North, accessed by the Kanichee Mine Road from Highway 11.
 The Kanichee Mine zone has been explored and mined discontinuously from as early as 1910.
 During the 20th century, it operated and closed down at least three times, with the most recent being from 1973 to 1976.
 To date, the discontinuous operation of Kanichee Mine has produced 4.2 million pounds of metal.
Hedley is an unincorporated town in southern British Columbia, Canada, named after Robert R. Hedley, the manager of the Hall Smelter in Nelson.
 Hedley is located at the foot of Nickel Plate Mountain in the Similkameen.
 The town had a population of approximately 400 as of 2005.
 In the early 1900s, Hedley's population peaked over 1,000 people, primarily due to the gold mining industry.
 The Hedley Museum and the Mascot Mine Museum display artifacts and photographs from this era.
Svenska Bergsbruk, formerly Wiking Mineral, is a junior mineral exploration and mine development company founded in 2005 primarily engaged in mine development and active exploration for base and precious metal deposits in Sweden that may lead to mining, focusing on precious and base metals.
The fineness of a precious metal object (coin, bar, jewelry, etc.) represents the weight of "fine metal" therein, in proportion to the total weight which includes alloying base metals and any impurities.
 Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement.
 For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry.
 Coin silver, which was used for making silver coins in the past, contains 90% silver and 10% copper, by mass.
 Sterling silver contains 92.5% silver and 7.5%, by mass, of other metals, usually copper.
Mercury silvering or fire gilding is a silvering technique for applying a thin layer of precious metal such as silver or gold (mercury gilding) to a base metal object.
 The process was invented during the Middle Ages and is documented in Vannoccio Biringuccio's 1540 book "De la pirotechnia".
 An amalgam of mercury and the precious metal is prepared and applied to the object which is then heated, sometimes in oil, vaporizing most of the mercury.
 The technique is dangerous since mercury is highly toxic.
 Mercury silvering can be detected through a variety of methods.
Coin debasement is the act of decreasing the amount of precious metal in a coin, while continuing to circulate it at face value.
 This was frequently done by governments in order to inflate the amount of currency in circulation; typically, some of the precious metal was replaced by a cheaper metal when the coin was minted.
 But when done by an individual, precious metal was physically removed from the coin, which could then be passed on at the original face value, leaving the debaser with a profit.
 Coin debasement was effected by several methods, including clipping (shaving metal from the coin's circumference) and sweating (shaking the coins in a bag and collecting the dust worn off).
The Outpost Island Mine was a gold and tungsten producer 94 kilometres southeast of Yellowknife, Northwest Territories on an island of Great Slave Lake.
 Gold was discovered here in 1935 by prospectors, and some development was undertaken in 1936-1938.
 Tungsten ores became valuable during World War II, so the owners (Slave Lake Gold Mines Limited) investigated the tungsten possibilities of the mine.
 It produced small amounts of gold, copper, and tungsten during 1941-1942, and then again in 1951-1952 during the Korean War.
 It was a small deposit and was not considered economic because of unpredictable tungsten market prices in the 1950s.
A precious metal is a naturally occurring metal of high economic value.
 Precious metal may also refer to:
A base metal is a common and inexpensive metal, as opposed to a precious metal such as gold or silver.
 A long-time goal of alchemists was the transmutation of a base (low grade) metal into a precious metal.
 In numismatics, coins often derived their value from the precious metal content; however, base metals have been also used in coins in the past and today.