# Aluminum > [!material-gem] Material Details > | | | > |---|---| > | **Aliases/Varieties** | Alum Crystals. Aluminum Alloy Foil. Sheet Aluminum. Clad Aluminum. Bare Aluminum. Aluminum Alloys. | > | **Category** | Gemstone | > | **Color(s)** | Silvery-white, metallic | > | **Cost** | —— | > | **Environment/Habitat** | —— | > | **Profession(s)** | [[Alchemist]], [[Jewelcrafter]], [[Tinkerer]] | > | **Qualities** | - Alchemical<br>- Healing<br>- Ornamental<br>- Protective | > | **Rarity** | —— | > | **Size** | —— | > | **Weight** | —— | > [!material-gem] Specifications > | | | > |---|---| > | **Crystal System** | Face-centered cubic | > | **Formations** | Abundant in compounds; never occurs in the metallic form in nature | > | **Formula** | Al | > | **Hardness** | 2.75 (Mohs) | > | **Mineral Class** | Elemental metal | > | **Primary Components** | aluminum | > | **Refractive Index** | —— | --- ## Description A lightweight, silvery metal with a high industrial potential. It protects from mental manipulation, enhances illusion magic, and aids in conjuring spirits and visions. ### Physical Description Aluminum is a soft, light, durable metal of low density, high conductivity, and adequate corrosion resistance. Appearance of the metal ranges from silvery-white to dull gray, depending on the surface roughness. It is non-toxic, non-magnetic, relatively cheap, easy to work with, and universally useful. Aluminum oxidizes easily, forming a protective layer on the surface as soon as it is exposed to air. --- ## Occurrence Aluminum is the most abundant metallic element in the planet's crust, occurring exclusively in rocks, never as a free metal. It is most abundant in feldspars, micas, and clays, with bauxite—a mixture of hydrated aluminum oxides—being the principal aluminum ore. Aluminum occurs in corundum and other gemstones, as well as in seawater, plants, and animals, but most of those are not viable sources for extraction. ### Extraction & Preparation Alum is sometimes mined as the mineral alunite, but more often extracted from bauxite with sulfuric acid. Pure aluminum is smelted from bauxite molten in cryolite in a purpose-built cell, and requires highly specialized equipment. Adding other metals and minerals (usually copper, silicon, magnesium, zinc, tin, or nickel) results in alloys, improving aluminum's mechanical properties. --- ## Properties ### Decorative Properties Ornamental-grade aluminum is a cheap, safe, hypoallergenic, and durable choice for jewelry. It does not tarnish or rust—the protective layer of oxide keeps the metal shiny with little to no cleaning required. However, unlike gold or silver, aluminum is too hard to easily resize—even magical rings made from aluminum will not adjust their owner's fingers. ### Industrial Properties Aluminum alloys are widely used in many branches of the industry: transportation, construction, packaging, production of machinery, equipment, tools, and electricity conductors. Alum crystals are used in tanning, dyeing, water treatment, deodorants, and to fireproof paper and cloth. As a silvery and malleable metal, aluminum is a non-toxic mercury substitute in alchemy, much safer to use but requiring much higher temperature to work with. ### Magical Properties Aluminum mirrors can reflect light outside of the visual spectrum and therefore, are used to conjure visions of spirits and far realms. Sheets of aluminum foil aid in image magic, visualization, manifesting, and casting illusions. It reflects and projects energy, protecting from unwanted mental influences, blocking telepathy and divination magic. Aluminum tools enhance mental abilities of the practitioner, simultaneously reducing the chance of random misfortunes. Aluminum is a favorite of explorers, bestowing luck during travels. Its high affinity for the element of air—and oxygen specifically— makes aluminum the metal of choice for spells, preparations, and items allowing water-breathing and cleansing the air from fumes, toxins, ash, and other impurities. Alloys lend aluminum the magical properties of other elements.