Mercury (element) long periods at elevated temperatures. It reverts to the elements upon heating near 400 °C, as was demonstrated by Joseph Priestley in an early synthesis of pure oxygen. Hydroxides of mercury are poorly characterized, as they are for its neighbors gold and silver. Being a soft metal, mercury forms very stable derivatives with the heavier chalcogens. Preeminent is mercury(II) sulfide, HgS, which occurs in nature as the ore cinnabar and is the brilliant pigment vermillion. Like ZnS, HgS crystallizes in two forms, the reddish cubic form and the black zinc blende form. The latter sometimes occurs naturally as metacinnabar. Mercury(II)
Ore dock Ore dock An ore dock is a large structure used for loading ore (typically from railway cars or ore jennies) onto ships, which then carry the ore to steelworks or to transshipment points. Most known ore docks were constructed near iron mines on the upper Great Lakes and served the lower Great Lakes. Ore docks still in existence are typically about wide, high, and vary from to in length. They are commonly constructed from wood, steel, reinforced concrete, or combinations of these materials. They are commonly used for loading bulk ore carriers with high mass, low-value ore, such as iron