Skip to content
LITHOEN

Chemical element

Aluminium

Also known as Aluminum

A major crustal element that can substitute for silicon in tetrahedral sites and also occupy larger octahedral ones — a dual role that makes it central to feldspars, micas and clays.

Classification

atomic number
13
symbol
Al
block
p

How this record is known

3
Settled consensus
Cited as the accepted position of the discipline.

3 of 3 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.

What Lithoen records

Each claim states how it is known and cites its evidence.

Established13 protons

Aluminium has atomic number 13: its nucleus contains 13 protons, and that is what makes it aluminium.

  • definition basis: Atomic number is definitional: an atom with a different proton count is a different element, whatever else it shares.

Evidence support: Supported by the cited evidence one source

Evidence: Commission on Isotopic Abundances and Atomic Weights (IUPAC) 2024 Primary authority

Established26.981538 u

The standard atomic weight of aluminium is 26.9815384(3), a single value because its isotopic composition does not vary appreciably between normal materials.

  • definition basis: CIAAW Standard Atomic Weights 2024; the parenthesised digits are the uncertainty in the last figures as published.
  • precision note: A property of the element as found in normal materials, not the mass of any individual atom.

Evidence support: Supported by the cited evidence one source

Evidence: Commission on Isotopic Abundances and Atomic Weights (IUPAC) 2024 Primary authority

In the knowledge graph

  • Aluminium essential constituent of Albite
  • Aluminium essential constituent of Almandine
  • Aluminium essential constituent of Anorthite
  • Aluminium essential constituent of Grossular
  • Aluminium essential constituent of Kaolinite
  • Aluminium essential constituent of Muscovite
  • Aluminium essential constituent of Pyrope

Record last updated 2026-09-06. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.