Rubidium oxide

Rubidium oxide is the <a href="/facts/Chemical_compound/37FXqqtv">chemical compound</a> with the <a href="/facts/Chemical_formula/hghUtthl">formula</a> Rb2O. Rubidium oxide is highly reactive towards water, and therefore it would not be expected to occur naturally. The rubidium content in <a href="/facts/Mineral/LkUFbNmv">minerals</a> is often calculated and quoted in terms of Rb2O. In reality, the rubidium is typically present as a component of (actually, an impurity in) <a href="/facts/Silicate/7NdthSRM">silicate</a> or <a href="/facts/Aluminosilicate/3gclsh2j">aluminosilicate</a>. A major source of rubidium is <a href="/facts/Lepidolite/tp55Ysme">lepidolite</a>, KLi2Al(Al,Si)3O10(F,OH)2, wherein Rb sometimes replaces K.
Rb2O is a yellow colored solid. The related species Na2O, K2O, and Cs2O are colorless, pale-yellow, and orange, respectively.
The <a href="/facts/Alkali_metal_oxide/3oYEEkE7">alkali metal oxides</a> M2O (M = Li, Na, K, Rb) crystallise in the antifluorite structure. In the antifluorite motif, the positions of the <a href="/facts/Anion/wrbwhF3z">anions</a> and <a href="/facts/Cation/wrbwhF3z">cations</a> are reversed relative to their positions in <a href="/facts/Calcium_fluoride/fCKHAvp1">CaF2</a>, with rubidium ions 4-coordinate (tetrahedral) and oxide ions 8-coordinate (cubic).

Rubidium oxide open-in-new

Rubidium oxide