The best specimens have come from Mammoth Mine, Tiger, Arizona . Leadhillite is trimorphous with the minerals macphersonite and susannite . Trimorphs are three different minerals that share the same chemistry, but have different structures. Leadhillite can be quite a popular collection mineral if it were only more available on the mineral markets. Color is colorless, white, sky blue, pale sea green, yellow and gray.
Color usually fades toward the center of the crystals.
Luster is resinous to adamantine. Cleavage surfaces are pearly. Crystals are transparent to translucent. Larger crystals may have a concave basal face. Pseudomorphs after susannite are also seen.