The major source of commercial thallium is the trace amounts found in the sulfide ores of copper, lead, zinc, and other metals.
The distinctive effects of thallium poisoning include loss of hair and damage to peripheral nerves.
Australian serial killer Caroline Grills was known as "Auntie Thally" for her choice of thallium as an agent to poison her victims.
Given their toxicity, thallium compounds were used as rat poisons in the past, but this use has been discontinued in many countries.
Thangka paintings, a syncretism of Chinese scroll-painting with Nepalese and Kashmiri painting, appeared in Tibet around the tenth century.
Thallium oxide has been used to manufacture glasses that have a high refractive index, its sulfide is useful in photocells, and its amalgam (alloy with mercury) is used in thermometers for low-temperature measurements.
Thallium is very soft and malleable and can be cut with a knife.
Dr. Fйlix-Roland Moumiй, a leader of the Cameroonian anticolonial armed struggle against France, was murdered by thallium poisoning on October 15, 1960.
In 2005, a 17-year-old girl in Numazu, Shizuoka Prefecture, Japan, admitted to attempting to murder her mother by lacing her tea with thallium, causing a national scandal.
Research on thallium's potential uses is ongoing, particularly to develop high-temperature superconducting materials for such applications as magnetic resonance imaging (MRI), storage of magnetic energy, magnetic propulsion, and electric power generation and transmission.
Thallium has 25 isotopes, with atomic masses that range from 184 to 210.
Manganese nodules, which are found on the ocean floor, also contain thallium, but nodule extraction is prohibitively expensive and potentially damaging for the environment.
The element thallium is reasonably abundant in the Earth's crust, at a concentration estimated to be about 0.7 milligrams per kilogram (mg/kg).
Thallium (chemical symbol Tl, atomic number 81) is a soft, malleable metal.
Crystals of thallium bromide-iodide have been used as infrared optical materials.
Agatha Christie, who worked as a pharmacist, used thallium as the agent of murder in her detective fiction novel The Pale Horse.
Thallium and its compounds have a number of uses.
A heavy layer of oxide builds up on thallium if left in air.
The name comes from thallium's bright green spectral emission lines.
Around the same time, an incidence of thallium poisoning was reported in Beijing.
The toxicity derives from the ability of thallium ions to replace other important cations such as sodium and potassium in the body.
Thallium was once an effective murder weapon before its effects became understood and an antidote (Prussian blue) was discovered.
The 1995 film The Young Poisoner's Handbook was based on the activities of Graham Frederick Young, who killed at least three people with thallium in the 1960s and 1970s.