• Pyrrhotite - Wikipedia

    en.wikipedia.org/wiki/Pyrrhotite Pyrrhotite is an iron sulfide mineral with the formula Fe (1-x) S (x = 0 to 0.2). 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 weakly magnetic.
  • Pyrrhotite: Mineral information, data and localities.

    www.mindat.org/min-3328.html Pyrrhotite is found with pentlandite in basic igneous rocks, veins, and metamorphic rocks. It is also often found with pyrite, marcasite, and magnetite. It has varying magnetic powers, depending on the number of Fe vacancies in the crystal structure.
  • How do pyrite and pyrrhotite damage building foundations ...

    www.americangeosciences.org/.../how-do-pyrite-and-pyrrhotite-damage-building-... Pyrite and pyrrhotite are minerals known as iron sulfides. When iron sulfides are exposed to water and oxygen, a series of chemical reactions breaks down the iron sulfides and forms new minerals called sulfates. These sulfates take up more space than the original iron sulfides. As they grow, the new sulfate minerals push against the surrounding rock, causing it to swell and crack.
  • Pyrrhotite | Definition of Pyrrhotite by Merriam-Webster

    www.merriam-webster.com/dictionary/pyrrhotite Pyrrhotite definition is - a bronze-colored mineral of metallic luster that consists of ferrous sulfide and is attracted by a magnet.
  • Pyrrhotite: The mineral pyrrhotite information and pictures

    www.minerals.net/mineral/pyrrhotite.aspx Pyrrhotite is commonly pseudomorphed by Pyrite, with complete replacement of the Pyrhottite by sparkling Pyrite crystals. Pyrrhotite is named from the Greek word pyrrhos, which means "color of fire".This is despite the fact that the usual color of Pyrrhotite is a bronze color rather than red; however its tarnish may have hints of sparkling red.
  • Pyrrhotite | mineral | Britannica

    www.britannica.com/science/pyrrhotite Pyrite (FeS 2) and pyrrhotite (Fe 1 - x S) are the most common sulfide minerals. Brassy yellow pyrite, often called “fool’s gold,” occurs variously as an accessory mineral in many rocks, in veins, and even as a chief component of some fossils. Pyrrhotite, which typically has…

    cfawalls.org/concretefacts/2018/03/16/understanding-pyrrhotite-in-concrete Pyrrhotite is the second most common iron sulfide in nature, and it is found associated with pyrite, marcasite, magnetite, and chalcopyrite (CSA 2014). Even so, aggregate that contains pyrrhotite, an unstable form of iron sulfide (Fe[1-x]S), in quantities that are able to be disruptive to concrete does not appear to be very common.
  • State: Foundations Are Failing At Least In Part Because Of ...

    www.courant.com/news/.../hc-concrete-investigation-results-20160509-story.html Pyrrhotite is a naturally occurring iron sulfide mineral that reacts with oxygen and deteriorates over time. The mineral was also cited in a widespread problem in Quebec as the mineral that ...
  • Crumbling Foundations - Connecticut

    portal.ct.gov/DOH/DOH/Programs/Crumbling-Foundations Pyrrhotite causes the slow deterioration of the concrete when exposed to oxygen and water. While the presence of pyrrhotite indicates the potential for concrete deterioration, its existence alone does not necessarily cause it. The cracking starts small and may take more than 10 years to over 30 years to appear. Horizontal cracks or cracks that ...
  • Deteriorating Concrete Foundations - Connecticut

    portal.ct.gov/DCP/.../Deteriorating-Concrete-Foundations The mineral pyrrhotite must be present to result in the foundation to deteriorate in the way observed. The minimum amount of pyrrhotite needed to trigger deterioration is not yet known. Becker’s Quarry, the main source of concrete aggregate for JJ Mottes, includes more than trace amounts of pyrrhotite, and is located on a vein of rock that ...