Search results
Results from the WOW.Com Content Network
Deep reddish purple. B: Normalized to [0–255] (byte) The color Byzantium is a particular dark tone of purple. It originates in modern times, and, despite its name, it should not be confused with Tyrian purple ( hue rendering ), the color historically used by Roman and Byzantine emperors. The latter, often also referred to as "Tyrian red", is ...
The Royal purple or Imperial purple was probably used until the time of Augustine of Hippo (354–430) and before the demise of the Roman Empire. Dye chemistry. Variations in colours of "Tyrian purple" from different snails are related to the presence of indigo dye (blue), 6-bromoindigo (purple), and the red 6,6'-dibromoindigo.
Shades of purple. There are numerous variations of the color purple, a sampling of which is shown below. In common English usage, purple is a range of hues of color occurring between red and blue. [1] However, the meaning of the term purple is not well defined. There is confusion about the meaning of the terms purple and violet even among ...
Molisch test (using α-napthol) indicating a positive result (see purple ring). Molisch's test is a sensitive chemical test, named after Austrian botanist Hans Molisch, for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric acid or hydrochloric acid to produce an aldehyde, which condenses with two molecules of a phenol (usually α-naphthol, though other ...
Purple of Cassius is a purple pigment formed by the reaction of gold salts with tin (II) chloride. It has been used to impart glass with a red coloration (see cranberry glass ), as well as to determine the presence of gold as a chemical test . Generally, the preparation of this material involves gold being dissolved in aqua regia, then reacted ...
The philosopher's stone [a] is a mythic alchemical substance capable of turning base metals such as mercury into gold or silver [b]; it was also known as "the tincture" and "the powder". Alchemists additionally believed that it could be used to make an elixir of life which made possible rejuvenation and immortality.
Colored gold is the name given to any gold that has been treated using techniques to change its natural color. Pure gold is slightly reddish yellow in color, [1] but colored gold can come in a variety of different colors by alloying it with different elements. Colored golds can be classified in three groups: [2] Alloys with silver and copper in ...
Color of chemicals. The color of chemicals is a physical property of chemicals that in most cases comes from the excitation of electrons due to an absorption of energy performed by the chemical. The study of chemical structure by means of energy absorption and release is generally referred to as spectroscopy .