# Lithium Oxide Colour

According to Chemistry LibreText:

Lithium is the lightest of all metals and is named from the Greek work for stone (lithos). It is the first member of the Alkali Metal family. It is less dense than water (with which it reacts) and forms a black oxide in contact with air.

However, if I'm not wrong, all alkali-metals react with non-metals to form white oxides. $$\text{Li}_2 \text{O}$$ is a white chemical compound, isn't it? What's with the site stating the opposite -- anything I'm possibly missing out on?

• It is white, as you say. The black stuff, as per wikipedia, is several substances.
– Ed V
Aug 24 '21 at 13:04
• Aldrich sell Lithium Oxide as a "white crystalline solid" sigmaaldrich.com/GB/en/product/aldrich/374725 Aug 24 '21 at 13:37
• One has to remember lithium reacts with nitrogen as well. Aug 24 '21 at 14:15

White cubic crystals; refractive index $$\pu{1.644}$$; density $$\pu{2.013 g/cm3}$$; melts at $$\pu{1,570 °C}$$; dissolves and decomposes in water ($$\pu{6.67 g/100g}$$ at $$\pu{0 °C}$$ and $$\pu{10.02 g/100g}$$ at $$\pu{100 °C}$$).
$$\ce{6Li + N2 -> \underset{black}{2Li3N}}$$