Search results
Results from the WOW.Com Content Network
Pyrite is distinguishable from native gold by its hardness, brittleness and crystal form. Pyrite fractures are very uneven, sometimes conchoidal because it does not cleave along a preferential plane. Native gold nuggets, or glitters, do not break but deform in a ductile way. Pyrite is brittle, gold is malleable.
This involves biting a mineral to see if it’s generally soft or hard. This was used in early gold exploration to tell the difference between pyrite (fools gold, hard) and gold (soft). Several of the minerals where a bite test could be diagnostic contain heavy metals. Even gold can be toxic, with repeated ingestion or in impure form. Hardness
Fracture differs from cleavage in that the latter involves clean splitting along the cleavage planes of the mineral's crystal structure, as opposed to more general breakage. All minerals exhibit fracture, but when very strong cleavage is present, it can be difficult to see.
The group is named for its most common member, pyrite (fool's gold), which is sometimes explicitly distinguished from the group's other members as iron pyrite. Pyrrhotite (magnetic pyrite) is magnetic, and is composed of iron and sulfur, but it has a different structure and is not in the pyrite group.
Chalcopyrite is much softer than pyrite and can be scratched with a knife, whereas pyrite cannot be scratched by a knife. [14] However, chalcopyrite is harder than gold, which, if pure, can be scratched by copper. [15] Additionally, gold is malleable, while chalcopyrite is brittle. [12] Chalcopyrite has a distinctive black streak with green ...
Sperrylite is a platinum arsenide mineral with the chemical formula PtAs 2 and is an opaque metallic tin white mineral which crystallizes in the isometric system with the pyrite group structure. It forms cubic, octahedral or pyritohedral crystals in addition to massive and reniform habits.
Ascending hydrothermal solutions rich in gold, sulfur and metals were channelled upward along major fracture and fault zones. Fluid that made it to the surface would have vented as hot springs and geysers. Localized erosion through the thrust sheet has formed windows into the underlying ore-bearing rocks. Adapted from Edwards and Atkinson (1985).
Pyrrhotite (pyrrhos in Greek meaning "flame-coloured") is an iron sulfide mineral with the formula Fe (1-x) S (x = 0 to 0.125). It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is