The designation “klaprothite” has been changed several times:

1) In 1824 the term “klaprothite” was coined by F.S. Beudant, who replaced it in 1832 with “klaprothine”, but the mineral thus designated was actually lazulite and therefore the name was abandoned.

2) In 1868 “klaprothite” was used again, this time by Thomas Petersen to designate another mineral, but this usage was rejected by George Brush, who changed it to “klaprotholite”. However, the material was identified in 1947 by Edward Nuffield as being a mixture of wittichenite and emplectite.

3) Later, G. Springer and S. Demirsoy studied this same material and suggested that klaprothite was a polymorph of emplectite, perhaps cuprobismuthite.

4) In 2015, a new mineral, a hydrated sulfate of Na and U, was named klaprothite. The formula is Na₆(UO₂)(SO₄)₄·4H₂O. It is extremely rare and has only been identified in a single occurrence in the USA.

Therefore, nowadays the designation “klaprothite” applies only to this new and rare sulfate. Designations in the literature should be evaluated carefully.