Thulium (Tm)

Thulium is the second-least abundant of the lanthanides, easy to work and silver-gray in color.

Core Principles & Analysis

• Per Teodor Cleve discovered thulium in 1879 and named it after Thule, the classical name for the far north.
• Excluding radioactive promethium, it is the least abundant of the lanthanides found in nature.
• Irradiated thulium-170 serves in portable X-ray sources, and thulium-doped lasers emitting near 2 micrometers are used in surgery.

Specifications & Metrics

• NUM: 69
• SYMBOL: Tm
• CATEGORY: Lanthanide