More commonly referred to as mercury oxide, this red orange solid is typically produced and distributed as an orange powder. In mineral form, it is referred to as montroydite, and is an exceptionally rare to find in naturally occurring deposits. The primary use for mercuric oxide is in the production of mercury via decomposition, which generates oxygen gas as a byproduct. Mercuric oxide is also used to manufacture cathodes in mercury battery cells. The primary concern with the storage and handling of mercuric oxide is that it is a highly topic substance if absorbed via skin contact, inhalation, or ingestion. Due to its natural decomposition process when exposed to light, mercury oxide is highly flammable, and if ignited it generates and releases additional oxygen gas that further increases and prolongs combustion. Furthermore, it reactions very violently with most reducing agents, chlorine, hydrogen peroxide, magnesium (heated), disulfur dichloride, and hydrogen trisulfide. Mercuric oxide is also highly unstable when combined with metals and elements such as sulfur and phosphorus.