Juangodoyite, Na₂Cu(CO₃)₂, a new mineral from the Santa Rosa mine, Atacama desert, Chile

Authors: Schlüter, Jochen; Pohl, Dieter

Source: Neues Jahrbuch für Mineralogie - Abhandlungen, Volume 182, Number 1, November 2005 , pp. 11-14(4)

Publisher: E. Schweizerbart'sche Verlagsbuchhandlung

Buy & download fulltext article:

Price: $39.00 plus tax (Refund Policy)

Abstract:

The new mineral juangodoyite has the ideal chemical formula Na₂Cu(CO₃)₂. It is monoclinic with space group P2₁/a. Cell parameters refined from X-ray powder diffraction data are (Å) a = 6.171(4), β = 8.171(5), c = 5.645(4), b = 116.23(2)°, V = 255.33(15) Å³, Z = 2. Juangodoyite is isostructural with synthetic sodium bis(carbonato)cuprate(II). The strongest reflections in the X-ray powder diffraction data are as follows: [d_meas.(Å), I, (hkl)]: 2.666 (100, 11–2), 4.258 (75, 11–1), 5.056 (66, 001), 2.619 (65, 210) and 4.575 (57, 110). Juangodoyite was found at the Santa Rosa mine near Iquique, Atacama desert, northern Chile. It occurs as fine-grained pseudomorphs, with crystallites up to 5 μm in size, after small laths of chalconatronite (Na₂Cu(CO₃)₂ · 3H₂O). Its colour is a vivid ultramarine blue. The calculated density is 2.984g/cm³, the calculated average refractive index is 1.571. Juangodoyite is closely associated with chalconatronite, malachite, calcite, anhydrite and sodium hydrogen carbonates. Chemical analyses gave (wt.%) Na₂O 28.27, CuO 33.77, CO₂ 38.45, sum 100.49. The resulting empirical formula calculated on the basis of 6 anions is Na_2.08Cu_0.98(C_1.99O₆).

The mineral was named after Juan Godoy, discoverer of the Chañarcillo silver mine.

Keywords: JUANGODOYITE; NEW MINERAL; CHALCONATRONITE; SODIUM BIS(CARBONATO)CUPRATE(II); CHILE; ATACAMA; SANTA ROSA MINE

Document Type: Research article

DOI: http://dx.doi.org/10.1127/0077-7757/2005/0026

Publication date: 2005-11-01

More about this publication?