The February, 1947 fall of the Sikhote-Alin iron in a remote part of eastern Siberia was, by far, the largest recorded meteorite event in history. While Campo del Cielo (Argentina), Muonionalusta (Sweden), and Gibeon (Namibia) may possibly have deposited more meteorites in terms of sheer tonnage, they all took place in prehistoric times. If those events were even seen by early humans, the witnesses lived thousands of years before the advent of writing and so no records exist.

The Millbillillie eucrite belongs to one of the rarest meteorite types. It is part of the HED group, which also includes howardites and diogenites. Eucrites are achondrites, meaning "not chondrites," so they are lacking in chondrules—the small, spherical, pre-solar grains that give the common chondrites their name. Millbillillie meteorites are volcanic rock from other worlds, and are comprised largely of silicate minerals. They are light in weight—similar in feel to terrestrial pumice—and are among those extremely uncommon meteorites which contain no iron, and show no attraction to a magnet. As such, they are less dense than the majority of meteorites and even a modest specimen of 6 or 7 grams can still be enjoyed and studied without magnification.

When falling through our atmosphere on the way to an impact with the Earth, most meteorites spin and tumble, often acquiring the interesting sculptural shapes. A very few maintain a fixed orientation towards our planet's surface. Heat ablation may cause those meteorites to acquire a conical, dome, or shield-shape, reminiscent of the heat shield on the Mercury, Gemini and Apollo space mission capsules and such meteorites are described as being oriented.