Rathoffite is a rare mineral that was first found in 1915 in Norway. Its name originates from Axel Hamberg, who named the mineral after the Norwegian mineralogist Hans Råthoff. The spelling of the word "Rathoffite" is pronounced as /ˈrætɒf aɪt/, with the stress placed on the second syllable. The "th" in "Rathoffite" is pronounced as a voiceless dental fricative, similar to the "th" in "think." Rathoffite occurs as small crystals in beryl-bearing granitic pegmatites and is typically associated with other rare minerals.
Rathoffite is a mineral that belongs to the thallium sulfosalt group. Its chemical composition is typically thallium arsenic sulfide, with the formula Tl2As2S3. Rathoffite is commonly found in hydrothermal veins associated with other sulfide minerals. It occurs as small, prismatic, or acicular crystals that may display a bluish-gray to black color.
This mineral has a distinct metallic luster and a grayish-black streak. It possesses a perfect cleavage along one direction, and its hardness ranges between 1.5 and 2 on the Mohs scale. Rathoffite has a high specific gravity, often exceeding 5.5, making it relatively heavy compared to many other minerals.
The name "rathoffite" is derived from its discoverer, August Rath, a Czech chemist. Rathoffite is primarily known for its rich thallium and arsenic content. Thallium is a rare and toxic element, and its presence in rathoffite makes the mineral of scientific interest and potentially hazardous. Therefore, caution should be exercised when handling or working with this mineral.
Due to its limited distribution and scarcity, rathoffite does not hold significant economic value. Instead, it is mainly sought after by mineral collectors and researchers for its unique crystal habit, rare composition, and association with other sulfosalt minerals. Rathoffite serves as a valuable indicator for identifying thallium-rich mineral deposits and contributes to the expanding knowledge of thallium-bearing minerals within the Earth's crust.