Mammothite is a mineral found in the Mammoth mine in Tiger, Arizona and also in Laurium, Attika, Greece.

The mammothite that is found in Arizona exist as euhedral crystals imbedded in micro granular, white colored anglesite with a saccharoidal texture.

In the Mammoth mine in Tiger, Arizona this mineral is associated with phosgenite, wulfenite, leadhillite and caledonite.

There are roughly 100 different kinds of mineral species in the Mammoth mine and about 25 of these are considered to be a part of an anomalous oxidized sequence.

The density was difficult to be measured due to the small size and an abundance of other minerals attached to it.

By using heavy liquid techniques, it was determined to be greater than 4.2g/cm3 but the idealized end member was calculated to be 5.25g/cm3.

It exhibits a 2V(measured)=80°, strong dispersion with r>v, and displays visible pleochroism with varying colors of shades of pale blue.

These crystals were analyzed by using an ARL-SEMQ electron microprobe that used an operating voltage of 15 kV and a sample current of 0.025 μA.