Realgar has a very bulky and muscular body with four arms, broad shoulders, and two legs. Her skim is bright red-orange with light red-orange markings, as well as four orange eyes with black pupils, no nose (with her gemstone acting as a nose), and a mouth with full lips and sharp teeth. Her hair is very dark red and is in a messy and choppy updo. Her gemstones are on her left eye and where her nose would be and are red-orange in color.
She wears a standard Homeworld uniform that’s tinted red with a Yellow Diamond insignia on her chest.
Realgar,α-As4S4, is an arsenic sulfide mineral, also known as "ruby sulphur" or "ruby of arsenic".
It is a soft, sectile mineral occurring in monoclinic crystals, or in granular, compact, or powdery form, often in association with the related mineral, orpiment (As2S3). It is orange-red in color, melts at 320 °C, and burns with a bluish flame releasing fumes of arsenic and sulfur.
Realgar is soft with a Mohs hardness of 1.5 to 2 and has a specific gravity of 3.5. Its streak is orange colored. It is trimorphous with alacranite and pararealgar.
Its name comes from the Arabic rahj al-ġār (رهج الغار, "powder of the mine"), via Catalan and Medieval Latin, and its earliest record in English is in the 1390s.
Realgar most commonly occurs as a low-temperature hydrothermal vein mineral associated with other arsenic and antimony minerals. It also occurs as volcanic sublimations and in hot spring deposits. It occurs in association with orpiment, arsenolite, calcite and barite. It is found with lead, silver and gold ores in Hungary, Bohemia and Saxony. In the US it occurs notably in Mercur, Utah; Manhattan, Nevada and in the geyser deposits of Yellowstone National Park.
It is commonly held that after a long period of exposure to light realgar changes form to a yellow powder known as pararealgar (β-As4S4). It was once thought that this powder was the yellow sulfide orpiment, but has been recently shown to be a distinct chemical compound.