Derriksite is a very rare

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

with the chemical formula Cu₄(UO₂)(SeO₃)₂(OH)₆•H₂O. It is a secondary mineral that contains

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

, uranium and the rarer

selenium Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...

. It is a bright green to duller bottle green colour. Its crystal habit is acicular, it is most likely to be found along with the uranyl selenium mineral demesmaekerite, but derriksite is much rarer than demesmaekerite. It is named after Jean Marie Francois Joseph Derriks (1912–1992), geologist and administrator of the Union Minière du Haut Katanga (UMHK). It has a

Mohs hardness The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by t ...

of about 2.

References

* * *{{cite journal , doi = 10.1255/jnirs.813 , title = An application of near infrared and mid-infrared spectroscopy to the study of uranyl selenite minerals: Derriksite, demesmaekerite, guilleminite and haynesite , year = 2008 , last1 = Frost , first1 = Ray , last2 = Jagannadha Reddy , first2 = B. , last3 = Dickfos , first3 = Marilla , journal = Journal of Near Infrared Spectroscopy , volume = 16 , issue = 5 , pages = 455–469, bibcode = 2008JNIS...16..455F , s2cid = 96401790 Uranium(VI) minerals Selenium minerals Copper(II) minerals Oxide minerals Orthorhombic minerals Minerals in space group 31

References

Further reading