Be · Mg · Ca · Sr · Ba · Ra
These metals have two outer electrons and commonly form +2 ions. They are generally less reactive than alkali metals, but the pure metals still differ greatly from the stable ions found in minerals and organisms.
Calcium is abundant in limestone, shells and bones. Magnesium sits at the centre of chlorophyll and is also used in lightweight alloys. Calcium and magnesium ions are major contributors to water hardness.
Beryllium is a special case: light and very stiff, it is useful in aerospace and scientific equipment. Its dust is hazardous, so machining it requires strict controls.