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Cinnabar has a mean refractive index near 3.2, a hardness between 2.0 and 2.5, and a specific gravity of approximately 8.1. The color and properties derive from a structure that is a hexagonal crystalline lattice belonging to the trigonal crystal system , crystals that sometimes exhibit twinning .
red cinnabar (α-HgS, trigonal, hP6, P3221) is the form in which mercury is most commonly found in nature. Cinnabar has rhombohedral crystal system. Crystals of red are optically active. This is caused by the Hg-S helices in the structure. [5] black metacinnabar (β-HgS) is less common in nature and adopts the zinc blende crystal structure (T 2 ...
[2] [3] The first recorded use of "vermilion" as a color name in English was in 1289. [4] [5] The term cinnabar is used in mineralogy and crystallography for the red crystalline form of mercury sulfide HgS. Thus, the natural mineral pigment is called "cinnabar", and its synthetic form is called "vermilion" from red lead. [2]
The sulphide minerals are a class of minerals containing sulphide (S 2−) or disulphide (S 2− 2) as the major anion. Some sulfide minerals are economically important as metal ores. The sulphide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, the sulpharsenides and the sulphosalts.
A research question is "a question that a research project sets out to answer". [1] Choosing a research question is an essential element of both quantitative and qualitative research . Investigation will require data collection and analysis, and the methodology for this will vary widely.
Characterization, when used in materials science, refers to the broad and general process by which a material's structure and properties are probed and measured. It is a fundamental process in the field of materials science, without which no scientific understanding of engineering materials could be ascertained.
Pure water (H 2 O) is an example of a compound. The ball-and-stick model of the molecule shows the spatial association of two parts hydrogen (white) and one part oxygen (red) A chemical compound is a chemical substance composed of many identical molecules (or molecular entities ) containing atoms from more than one chemical element held ...
Alchemical symbols were used to denote chemical elements and compounds, as well as alchemical apparatus and processes, until the 18th century. Although notation was partly standardized, style and symbol varied between alchemists.