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Material World
Material · Processed natural

Asbestos

Naturally fibrous silicate minerals that will not burn — an almost ideal industrial material, and a carcinogen for exactly the reason it works.

Insulator Refractory

Asbestos is not one mineral but a commercial name for six silicates that happen to crystallise as fine flexible fibres. Chrysotile, a serpentine mineral, accounts for the great majority; the rest are amphiboles, and are more dangerous.

As a material it was close to ideal. It does not burn, does not rot, resists most chemicals, insulates against heat and electricity, is strong in tension, and could be spun, woven, or mixed into cement and plastic. It was cheap, and it was put into everything.

Economic significance

The property that made it useful is the property that makes it lethal. A fibre thin enough to be woven is thin enough to be inhaled deep into the lung, and durable enough that the body cannot break it down or remove it. It stays, and decades later causes asbestosis, lung cancer or mesothelioma — a cancer of the lung lining with essentially no other cause.

The latency is the reason the epidemic ran so long. Exposure and disease are separated by twenty to fifty years, so the consequences of installing it in the 1960s were still arriving in the 2000s, and the industry's internal knowledge of the hazard preceded public acknowledgement by decades — which is why asbestos litigation is among the largest in legal history.

Most of the remaining problem is not new production but what was already installed. Removing it disturbs it, so the standard advice for undamaged material is to leave it alone and record where it is.

Medium confidence Weak evidence

How we know: checked recently · only one source, so there is nothing to cross-check it against · stated directly by the source.

How this connects

Where a connection has been confirmed by an outside reference, that reference is named beside it.

is sourced from

  • Serpentinite — rock · chrysotile is serpentine that crystallised across an opening crack, which is why it occurs as cross-fibre veins and why serpentinite hosts most of what was ever mined

contains

  • Magnesium — element · chrysotile is a magnesium silicate, the same composition as the serpentine around it and a different habit
  • Silicon — element · the silicate framework, rolled into the fibres that made it useful and lethal at once

is commonly confused with

  • Mineral wool — material · both mineral fibres, and the distinguishing property is biopersistence: asbestos stays in lung tissue for decades and mineral wool fibres dissolve in weeks

Sources

  • Wikidata
    Wikimedia Foundation · Creative Commons CC0 1.0 Universal (public domain dedication)
  • Material World
    Our own writing

Questions this page answers

Where it comes from, and what it becomes

Follow Asbestos back to what it starts as, and forward into what it becomes. Each step is a documented one — a real route material takes, not a chain of inference.

Upstream — what it comes from

  • Asbestos → is sourced from (chrysotile is serpentine that crystallised across an opening crack, which is why it occurs as cross-fibre veins and why serpentinite hosts most of what was ever mined) → Serpentinite → is sourced from (serpentinite is hydrated peridotite; the protolith is the mantle rock itself) → Peridotite → is composed of (the mineral that defines the rock and gives it its name — a peridotite is olivine-dominant by definition) → Olivine
  • Asbestos → is sourced from (chrysotile is serpentine that crystallised across an opening crack, which is why it occurs as cross-fibre veins and why serpentinite hosts most of what was ever mined) → Serpentinite → is composed of (produced by the reaction itself, from the iron released as olivine breaks down; it is why serpentinite is magnetic) → Magnetite
  • Asbestos → is sourced from (chrysotile is serpentine that crystallised across an opening crack, which is why it occurs as cross-fibre veins and why serpentinite hosts most of what was ever mined) → Serpentinite → is composed of (relict from the peridotite, surviving the hydration that destroyed everything around it — and recovered from serpentinite for that reason) → Chromite
  • Asbestos → is sourced from (chrysotile is serpentine that crystallised across an opening crack, which is why it occurs as cross-fibre veins and why serpentinite hosts most of what was ever mined) → Serpentinite → is composed of (where carbon dioxide-bearing fluid carried the alteration a stage further, which is the origin of much of the talc mined worldwide) → Talc
  • Asbestos → is sourced from (chrysotile is serpentine that crystallised across an opening crack, which is why it occurs as cross-fibre veins and why serpentinite hosts most of what was ever mined) → Serpentinite → is sourced from (serpentinite is hydrated peridotite; the protolith is the mantle rock itself) → Peridotite → is composed of (the magnesian end of the olivine series, and what mantle olivine actually is — around ninety per cent forsterite in most peridotite) → Forsterite
  • Asbestos → is sourced from (chrysotile is serpentine that crystallised across an opening crack, which is why it occurs as cross-fibre veins and why serpentinite hosts most of what was ever mined) → Serpentinite → is sourced from (serpentinite is hydrated peridotite; the protolith is the mantle rock itself) → Peridotite → is composed of (an early-crystallising accessory that can accumulate into seams of near-pure ore — the source of essentially all the world's chromium) → Chromite