Thallium

About Thallium

Discovered by its bright green spectral line, from the Greek thallos, a green shoot. Odorless and tasteless, thallium was the poison of choice in countless true crime stories and was once called inheritance powder, until tests were developed and sales were restricted. Now used in infrared optics, gamma ray detectors, and specialty glass. Discovered by flame spectroscopy the same year as cesium.