Ovo black and cobalt glasses free#

Ĭobalt is the active center of a group of coenzymes called cobalamins. This is to clean it of its sulfur content, which is very polluting when burned and causes acid rain. Cobalt is also used in the petroleum industry as a catalyst when refining crude oil. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy gamma rays. Cobalt occurs naturally as only one stable isotope, cobalt-59. The compounds cobalt silicate and cobalt(II) aluminate (CoAl 2O 4, cobalt blue) give a distinctive deep blue color to glass, ceramics, inks, paints and varnishes. Ĭobalt is primarily used in lithium-ion batteries, and in the manufacture of magnetic, wear-resistant and high-strength alloys. World production in 2016 was 116,000 tonnes (114,000 long tons 128,000 short tons) (according to Natural Resources Canada), and the DRC alone accounted for more than 50%. The Copperbelt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. The element is, however, more usually produced as a by-product of copper and nickel mining. Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the kobold. Miners had long used the name kobold ore ( German for goblin ore) for some of the blue pigment-producing minerals they were so named because they were poor in known metals and gave off poisonous arsenic-containing fumes when smelted.

Ovo black and cobalt glasses free#

The free element, produced by reductive smelting, is a hard, lustrous, silvery metal.Ĭobalt-based blue pigments ( cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was for a long time thought to be due to the known metal bismuth.

As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. It may be obscured by other fluorescent species or colorants.Cobalt is a chemical element it has symbol Co and atomic number 27. Sb (Antimony) - A bluish, whitish often rather weak fluorescence. The greenish-yellow might be absorbed by the purple color of the body of the glass itself. Mn usually requires a level of ~ 0.5% (?) to be readily visible. This is usually not at all a strong fluorescence. Mn (Manganese) - A moderately strong 'lemonade-like' greenish-yellow, often somewhat turbid. The Pb fluorescence is an icy-blue color and emanates from within the body of the glass.) (Don't mistake the reflection of visible purple light from the UV lamp for Pb fluorescence. Pb normally fluoresces more strongly than manganese or antimony. High-lead glasses are usually colorless. The fluorescence becomes noticeable at a level of about 5%, and is strong by about 10-15%. The fluorescence is visible under both long-wave and short-wave UV. Pb (Lead) - A strong icy-blue response, but not normally as strong as U. Ancient glasses contain at most a few ppm of U - not nearly enough to cause any UV fluorescence. The color is usually obtained by adding ~0.5 % U2O3. Once you have seen the color, you will remember it. You can tell a uranium-containing glass just by looking at it. The color of the glass itself in visible light is usually a bright yellow or yellowish-green, or an amber color in a lead matrix. U (Uranium)- A very strong bright-green response. Leaving out the exotic elements not found in ordinary glasses, the responses are more-or-less as follows: The fluorescent response depends on several factors: primarily the elements present, sometimes matrix effects, the concentrations, the wavelength of the exciting radiation, the intensity of the exciting radiation, possibly the redox state of the elements, colorants that might be present, etc. There are several elements that will cause common glasses to fluoresce. Robert Brill, Research Scientist Emeritus:

16 Lampworking/Flameworking/Scientific GlassblowingĮxample of uranium glass.

4 Glass Labor History/Working Conditions.