Biominerals are widely exploited to harden or stiffen tissues in living organisms, with calcium-, silicon-, and iron-based minerals being most common. In notable contrast, the jaws of the marine bloodworm Glycera dibranchiata contain the copper-based biomineral atacamite [Cu2(OH)3Cl]. Polycrystalline fibers are oriented with the outer contour of the jaw. Using nanoindentation, we show that the ...

The room temperature co-precipitation of ferrous and ferric iron under alkaline conditions typically yields superparamagnetic magnetite nanoparticles below a size of 20 nm. We show that at pH  =  9 this method can be tuned to grow larger particles with single stable domain magnetic (> 20-30 nm) or even multi-domain behavior (> 80 nm). The crystal growth kinetics resembles surprisingly observati...

[1] ODP/IODP Hole 1256D penetrates an in situ section of ocean crust formed at the East Pacific Rise, through lavas and sheeted dikes and ∼100 m into plutonic rocks. We use mineralogy, oxygen isotopes, and fluid inclusions to understand hydrothermal processes. The lavas are slightly altered at low temperatures (<150°C) to phyllosilicates and iron oxyhydroxides, with a stepwise increase in grade...

The Cabaçal deposit is located in SW Amazonian Craton, Mato Grosso State, Brazil, with important Au-Zn-Cu mineralization. ore hosted by the Alto Jauru orogenic rocks (1.79-1.74 Ga) comprised of felsic volcanic and volcanoclastic mineralizations occur as bands concordant mylonitic foliation, breccias, quartz-carbonate veins rock-disseminated, polymetallic comprises chalcopyrite, pyrite, marcasit...

Frataxin is a highly conserved protein found in both prokaryotes and eukaryotes. It is involved in several central functions in cells, which include iron delivery to biochemical processes, such as heme synthesis, assembly of iron-sulfur clusters (ISC), storage of surplus iron in conditions of iron overload, and repair of ISC in aconitase. Frataxin from different organisms has been shown to unde...

We document the discovery of the first granular iron formation (GIF) of Archaean age and present textural and geochemical results that suggest these formed through microbial iron oxidation. The GIF occurs in the Nconga Formation of the ca. 3.0-2.8 Ga Pongola Supergroup in South Africa and Swaziland. It is interbedded with oxide and silicate facies micritic iron formation (MIF). There is a stron...

Key constraints related to the nature of alteration and mineralization in geologically complex economically important iron oxide copper–gold (IOCG) systems remain highly speculative, especially, physicochemical characteristics hydrothermal fluids. This study was conducted on samples from Khetri Copper Belt (KCB) western India that hosts several IOCG-type deposits. The aims constrain qualitative...