Dark Moon is primarily hotsonite, an aluminum phosphate mineral that is considered a "sister stone" to turquoise and variscite due to its similar composition and origins, though it is chemically distinct.

The "Dark Moon" designation typically describes the material's unique visual characteristics. It generally has a creamy white or light-colored base. It features striking, often black, gray or dark brown matrix patterns. More rare examples display yellow or orange coloration, which adds a brighter, high-contrast appearance and increases visual appeal.

The Hubei Province in China is a primary source for this material, with the name "Dark Moon Hubei turquoise" sometimes used in the lapidary market, even though it's technically hotsonite.