Blue is one of the seven colours into which the rays of light divide themselves when refracted through a glassprism, seen in nature in the clear expanse of the heavens; the term is also applied to a dye or pigment of this hue.
The substances used as blue pigments are of very different natures, and derived from various sources; they are all compound bodies, some being natural and others artificial. They are derived almost entirely from the vegetable and mineral kingdoms. The principal blues used in painting are ultramarine, which was originally prepared from lapis-lazuli or azure-stone - a mineral found in China and other oriental countries - but, as now prepared, it is an artificial compound of china-clay, carbonate of soda, sulphur, and charcoal; Prussian or Berlin blue, which is a compound of cyanogen and iron; blue bice, prepared from carbonate of copper; indigo blue, from the indigo plant. Besides these, there are numerous other blues used in art, as blue-verditer, smalt- and cobalt-blue, from cobalt, lacmus or litmus, etc.
Before the discovery of aniline or coal-tar colours dyers chiefly depended for their blues on woad, archil, indigo, and Prussian blue, but now a series of brilliant blues are obtained from coal-tar, possessing great tinctorial power and various degrees of durability.
Blue as a colour ranges from green-blue (turquoise) through to purple-blue (indigo).
Alice blue - A very light greenish-blue colour.
Aquamarine - A bluish-green colour.
Azure - A deep blue colour reminiscent of the sky.
Aquamarine - A pale greenish-blue colour.
Bice blue - A medium blue colour
Cambridge blue - A light blue colour.
Cobalt blue - A deep blue colour with a greenish-tint. The colour of old blue glass.
The ruddy duck (Oxyura jamaicensis) is a North American duck now established in Britain following escapes from the wildlife park at Slimbrige, Gloucestershire. It is a compact, dumpy, divingduck about 40 centimetres long with a short stiff tail which is often held cocked at an angle. The male has orange-chestnut body plumage with a white stern, white cheeks and a black cap. The bill is a striking turquoise colour. In the spring the male duck performs a curious chest-beating display which results in a froth of bubbles forming on the water. Research Ruddy Duck
Ceruleite is a sky-blue coloured arsenate mineral similar in appearance and hardness to turquoise first discovered in the Emma Louisa gold mine in Huanaco, Chile and confirmed as a distinct mineral in 1900. Research Ceruleite
Cornetite is a rare, brittle, secondary mineral with a chemical composition similar to turquoise. Cornetite is formed in the weatheredoxidation zones of copper sulphide ore bodies and is found in association with brochantite, chrysocolla, liberthenite, limonite, malachite and pseudomalachite. Cornetite was first discovered in 1912 and was confirmed as a distinct mineral in 1917, subsequently being named after the Belgian geologist Jules Cornet. Cornetite is a naturally occurring hydrous phosphate of copper, as is also turquoise. Research Cornetite
Turquoise (also known as calaite) is a mineral of secondary origin usually found in small veins and stringers. Turquoise is a hydrous phosphate of alumina containing a little copper. It has a blue, or bluish green, colour, and usually occurs in reniform masses with a botryoidal surface. It has a relative hardness of 6. Turquoise is susceptible of a high polish, and when of a bright blue colour is much esteemed as a gem. The finest specimens come from Persia. It is also found in New Mexico and Arizona, and is regarded as identical with the chalchihuitl of the Mexicans. Research Turquoise
The Turquoise was a French Saphir Class minelayer submarine of 669 tons displacement surfaced launched in 1929. The Turquoise was powered by Vickers-Normand 4-cycle diesel engines providing a top speed of 12 knots surfaced and 9 knots submerged and a range of 4000 km surfaced. She carried a complement of 40 and armaments consisted of one 3-inch anti-aircraft gun; five 21.7 inch torpedo tubes and thirty-two mine laying chutes, each fitted with a 460 lb mine. Research Turquoise
HMS Turquoise (formerly the Warwickshire) was a British armed trawler of 641 tons displacement launched in 1935 and used by the British navy during the Second World War for anti-submarine training. HMS Turquoise had a top speed of 12 knots and was armed with one 4-inch gun and depth charges. Research Turquoise II
The Turquoise is a French Rubis class nuclear submarine with a displacement of 2400 tons. She is powered by two turbo alternators; one main motor (with an emergency electric motor); one CAS 48 pressurised water-cooled nuclear reactor rated at 48 MW; one Jeumont-Schneider auxiliary diesel electric motor, providing a top speed of 25 knots. Two alternating crews each of 67 personnel provide the ships complement. Armaments consist of Aerospatiale SM 39 Exocet anti-ship missiles launched from four 533 mm torpedo tubes; ECAN L5 Mod 3 dual purpose torpedoes; or up to 32 FG 29 mines carried in lieu of torpedoes. Research Turquoise III
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Ruddy Duck
