Before revision: Some of these radium-treated diamonds—which are still found in markets and can be detected by particle detectors such as the Geiger counter, the scintillation counter, or the semiconductor detector—are so high in radiation emission that they may darken photographic film in minutes.
After revision: Some of these radium-treated diamonds—which are occasionally put on sale and can be detected by particle detectors such as the Geiger counter, the scintillation counter, or the semiconductor detector—are so high in radiation emission that they may darken photographic film in minutes.