Cinnabar (/ˈsɪnəˌbɑːr/; from Ancient Greek κιννάβαρι (kinnábari)),[7] or cinnabarite (/ˌsɪnəˈbɑːraɪt/), also known as mercurblende is the bright scarlet to brick-red form of mercury(II) sulfide (HgS).

In Roman times, cinnabar was highly valued as paint for walls, especially interiors, since it darkened when used outdoors due to exposure to sunlight.

Associated modern precautions for the use and handling of cinnabar arise from the toxicity of the mercury component, which was recognized as early as ancient Rome.

[11] Cinnabar is generally found in a massive, granular, or earthy form and is bright scarlet to brick-red in color, though it occasionally occurs in crystals with a nonmetallic adamantine luster.

[14] Its mean refractive index is 3.08 (sodium light wavelengths),[15] versus the indices for diamond and the non-mineral gallium(III) arsenide (GaAs), which are 2.42 and 3.93, respectively.

[23] Cinnabar is still being deposited, such as from the hot waters of Sulphur Bank Mine[24] in California and Steamboat Springs, Nevada (United States).

"[33] Cinnabar has been used for its color since antiquity in the Near East, including as a rouge-type cosmetic,[31] in the New World since the Olmec culture, and in China for writing on oracle bones as early as the Zhou dynasty.

[citation needed] Cinnabar's use as a color in the New World, since the Olmec culture,[34] is exemplified by its use in royal burial chambers during the peak of Maya civilization, most dramatically in the 7th-century tomb of the Red Queen in Palenque, where the remains of a noble woman and objects belonging to her in her sarcophagus were completely covered with bright red powder made from cinnabar.

[36] The danger of mercury poisoning may be reduced in ancient lacquerware by entraining the powdered pigment in lacquer,[37][page needed] but could still pose an environmental hazard if the pieces were accidentally destroyed.

[citation needed] Two female mummies dated AD 1399 to 1475 found in Cerro Esmeralda in Chile in 1976 had clothes colored with cinnabar.