What is "mercury oxide"

Mercury(II) oxide, also called mercuric oxide or simply mercury oxide, has a formula of Hg O. It has a red or orange color. Mercury(II) oxide is a solid at room temperature and pressure. The mineral form montroydite is very rarely found.

Mercury oxide can refer to:

• Mercury(I) oxide (mercurous oxide), HgO
• Mercury(II) oxide (mercuric oxide), HgO

Mercury(I) oxide, also known as mercurous oxide, is an inorganic metal oxide with the chemical formula HgO.

It is a brown/black powder, insoluble in water, toxic but without taste or smell. It is chemically unstable and converts to mercury(II) oxide and mercury metal.