Halloysite
ID: 128
Halloysite
Chemical Formula
Al2Si2O5(OH)4
Hardness (Mohs)
1 - 2
Crystal System
Monoclinic
Streak
White or paler than the color.
Luster
Earthy, Waxy
Diaphaneity
Translucent, Opaque
Color
White, yellowish white, reddish white, brownish white, greenish white; also tan, chocolate brown, reddish, bluish, or greenish.
Crystal Habit / Mode of Occurrence
Typically found as extremely fine-grained clayey masses, earthy to somewhat waxy looking. Often has a tubular morphology at the nanometer scale.
Fun Facts
Halloysite is known for its unique hollow tubular structure at the nanoscale, making it a natural "nanocarrier" for various substances.