Uranyl hydroxide
Uranyl hydroxide is a hydroxide of uranium with the chemical formula UO(OH) in the monomeric form and (UO)(OH) in the dimeric; both forms may exist in normal aqueous media. Uranyl hydroxide hydrate is precipitated as a colloidal yellowcake from oxidized uranium liquors near neutral pH.
Aluminium hydroxide
Gibbsite is also known as hydrargillite, named after the Greek words for water (') and clay ('). The first compound named "hydrargillite" was thought to be aluminium hydroxide, but was later found to be aluminium phosphate; despite this, both "gibbsite" and "hydrargillite" are used to refer to the same polymorphism of aluminium hydroxide, with "gibbsite" used most commonly in the United States and "hydrargillite" used more often in Europe. In 1930, it was referred to as "α-alumina trihydrate" to contrast it with bayerite, which was called "β-alumina trihydrate" (the alpha and beta designations were used to differentiate the more- and less-common forms respectively). In 1957, a symposium on alumina nomenclature attempted to develop a universal standard, resulting in gibbsite being designated γ-Al(OH), bayerite becoming α-Al(OH), and nordstrandite being designated Al(OH). Based on their crystallographic properties, a suggested nomenclature and designation is for gibbsite to be α-Al(OH), bayerite to be designated β-Al(OH), and both nordstrandite and doyleite are designated Al(OH). Under this designation, the α and β prefixes refer to hexagonal, close-packed structures and altered or dehydrated polymorphisms respectively, with no differentiation between nordstrandite and doyleite.