Vanadinite - Pb₅(VO₄)₃Cl

Habit: Orange red, ruby red, brownish red or brown yellow to pale straw yellow. Crystals short to long prismatic with smooth faces and sharp edges; acicular to hair-like, occasionally hollow prism crystals with rounded domes in parallel grouping. Subresinous to admantine luster; subtransparent to nearly opaque. Brownish yellow streak.

Environment: A secondary mineral found in the oxidized zone of lead deposits.

Etymology: From the vanadium in its composition.

Along with carnotite and roscoelite, vanadinite is one of the main industrial ores of the element vanadium. Small amounts of vanadium can significantly improve the properties of certain ferrous (iron-containing) alloys. Vanadium steel is particularly strong and hard, with considerable shock resistance. Vanadium and aluminum are used together to give the required strength to titanium alloys used in jet engines and high-speed airframes.