Akdalaite

Akdalaite (IMA symbol: Akd^[1]) is a very rare mineral found in Kazakhstan and has the formula 5Al₂O₃·H₂O.^[2] It was formerly believed to be 4Al₂O₃·H₂O. It is therefore the same as tohdite an artificially produced phase. Studies on the crystal structure and spectra indicate that this is an aluminium oxide hydroxide.^[3]

Akdalaite
General
Category	Minerals
Formula	5Al2O3·H2O
IMA symbol	Akd
Identification
Color	White, pale greenish yellow in thin section
Fracture	Irregular/uneven
Mohs scale hardness	7–7.5
Luster	Vitreous
Streak	White
Diaphaneity	Translucent
Specific gravity	3.68