Element 20 · Alkaline Earth Metal
Calcium
The fifth most abundant element in the Earth's crust — but pure calcium metal has very limited commercial application.
Element Facts
SYMBOL
Ca
ATOMIC NO.
20
ATOMIC WEIGHT
40.08
CATEGORY
Alkaline Earth Metal
PERIOD
Period 4
GROUP
Group 2
Quick Overview
Calcium is element 20, a soft silvery alkaline earth metal. Pure calcium oxidises rapidly in air to form a grey-white surface coating. Most "calcium" in the world is in the form of calcium carbonate (limestone, marble, chalk) or calcium phosphate (in bones and teeth).
Discovery & History
Pure calcium metal has had limited historical applications because of its reactivity. Calcium compounds — particularly limestone in cement, mortar, and steel making — are foundational to construction and metallurgy.
Where It's Used
Pure calcium is used in metallurgy as a deoxidiser and desulfuriser in steelmaking, and as an alloying element in some lead alloys (notably lead-calcium battery alloys, replacing antimony). It is also used in calcium-aluminium alloys for special applications.
Can You Sell It?
Why QuickStop Metals doesn’t buy Calcium:
Pure calcium oxidises rapidly and is supplied as a chemical commodity directly to industrial users. There is no general scrap market for calcium metal. The element's primary appearances in the built environment are as compounds (cement, plaster, glass) rather than recoverable metal.
Price Guide
Calcium metal is supplied directly to industrial users and not openly traded.