Where is the better Mercury oxide

Where is the better Mercury oxide? For many people this is a strange object, and here's the introduction to it:

Mercury oxide mercury (II) (oxidation) is a kind of alkaline oxide, as inorganic substances, chemical formula for HgO, bright red or orange-red scaly crystalls or crystal powder, almost insoluble in water, insoluble in ethanol, 500 ℃ when the decomposition. Virulent, irritating. Mercury oxide can be used to make other mercury compounds, as well as electrode materials in catalysts, pigments, antimicrobials and mercury batteries.