This was based on observation of the metals and their physical properties.Miners in the age of alchemy also gave bismuth the name tectum argenti, or "silver being made" in the sense of silver still in the process of being formed within the Earth.Bismuth was also known to the Incas and used (along with the usual copper and tin) in a special bronze alloy for knives. Beginning with Johann Heinrich Pott in 1738, Carl Wilhelm Scheele, and Torbern Olof Bergman, the distinctness of lead and bismuth became clear, and Claude François Geoffroy demonstrated in 1753 that this metal is distinct from lead and tin. Characteristics
Physical characteristics
Bismuth is a brittle metal with a dark, silver-pink hue, often with an iridescent oxide tarnish showing many colors from yellow to blue. The spiral, stair-stepped structure of bismuth crystals is the result of a higher growth rate around the outside edges than on the inside edges. The variations in the thickness of the oxide layer that forms on the surface of the crystal cause different wavelengths of light to interfere upon reflection, thus displaying a rainbow of colors. When burned in oxygen, bismuth burns with a blue flame and its oxide forms yellow fumes. Its toxicity is much lower than that of its neighbors in the periodic table, such as lead, antimony, and polonium. No other metal is verified to be more naturally diamagnetic than bismuth. (Superdiamagnetism is a different physical phenomenon.)
In comparison with lead chromates, it does not blacken due to hydrogen sulfide in the air (a process accelerated by UV exposure) and possesses a particularly brighter color than them, especially the lemon, which is the most translucent, dull, and fastest to blacken due to the higher percentage of lead sulfate required to produce that shade. It is also used, on a limited basis due to its cost, as a vehicle paint pigment. A catalyst for making acrylic fibers. As an electrocatalyst in the conversion of CO2 to CO. Ingredient in lubricating greases. In crackling microstars (dragons eggs) in pyrotechnics, as the oxide, subcarbonate or subnitrate. As catalyst for the fluorination of arylboronic pinacol esters through a Bi(III)/Bi(V) catalytic cycle, mimicking transition metals in electrophilic fluorination. Toxicology and ecotoxicology
See also bismuthia, a rare dermatological condition that results from the prolonged use of bismuth.Scientific literature indicates that some of the compounds of bismuth are less toxic to humans via ingestion than other heavy metals (lead, arsenic, antimony, etc.) presumably due to the comparatively low solubility of bismuth salts. Its biological half-life for whole-body retention is reported to be 5 days but it can remain in the kidney for years in people treated with bismuth compounds.Bismuth poisoning can occur and has according to some reports been common in relatively recent times. As with lead, bismuth poisoning can result in the formation of a black deposit on the gingiva, known as a bismuth line.