The easily worked oxidised ore was largely depleted and the underlying sulfide deposits were proving difficult and costly to treat.
In this process, the silver is reduced and lead sulfide is formed.
The black color which then results from the addition of sulfur is likely to be due to the formation of lead sulfide.
Further, paleomagnetic measurements are going to reveal the relationship between the deposition of the black shale and formation of the iron sulfide.
We are studying microbes in hydrothermal environments that obtain metabolic energy from mineral substrates, particularly metal sulfides.
When acetic acid was poured over the produce ("liver of sulfur," which contains mostly potassium sulfide), sulfur precipitated due to an oxidation of the sulfide.
The main argument for this is that in a chemical reaction, the sulfide ion should be a good nucleophile for the reaction.
Second, elemental arsenic does not combust with copper in alloying as in the case of arsenic sulfide.
