lead silicate
21Han purple and Han blue — (also called Chinese purple and Chinese blue) are synthetic barium copper silicate pigments that were developed in China at least 2,000 years ago. Han purple and Han blue were used in ancient and imperial China from the Western Zhou period (1207… …
22Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
23industrial glass — Introduction solid material that is normally lustrous and transparent in appearance and that shows great durability under exposure to the natural elements. These three properties lustre, transparency, and durability make glass a favoured… …
24chemical element — Introduction also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed. This article considers the… …
25hydrosphere — /huy dreuh sfear /, n. the water on or surrounding the surface of the globe, including the water of the oceans and the water in the atmosphere. [1885 90; HYDRO 1 + SPHERE] * * * Discontinuous layer of water at or near the Earth s surface. It… …
26metamorphic rock — Any of a class of rocks that result from the alteration of preexisting rocks in response to changing geological conditions, including variations in temperature, pressure, and mechanical stress. The preexisting rocks may be igneous, sedimentary,… …
27Portland cement — is the most common type of cement in general usage in many parts of the world, as it is a basic ingredient of concrete, mortar, stucco and most non specialty grout. It is a fine powder produced by Portland cement clinker (more than 90%), a… …
28Graphite — For other uses, see Graphite (disambiguation). Graphite Graphite specimen General Category Native element mineral …
29pottery — /pot euh ree/, n., pl. potteries. 1. ceramic ware, esp. earthenware and stoneware. 2. the art or business of a potter; ceramics. 3. a place where earthen pots or vessels are made. [1475 85; POTTER1 + Y3] * * * I One of the oldest and most… …
30Silicon — Not to be confused with the silicon containing synthetic polymer silicone. aluminium ← silicon → phosphorus C ↑ Si ↓ Ge …
