Hexaplex trunculus degrades, resulting in blue only. Nonetheless, archeologists have confirmed Hexaplex trunculus as the species used to create the purple-blue dye; large numbers of shells were recovered from inside ancient live-storage chambers that were used for harvesting. Apparently, 10- to 12,000 murex yielded only one gram of dye. Because of this, the dye was highly prized. Also known as "Royal Purple", it was prohibitively expensive and was only used by the highest ranking aristocracy. A similar dye, "Tyrian purple", which is purple-red in color, was made from a related species of marine snail, "Murex brandaris". This dye (alternatively known as "imperial
Carbene dye dyed. For example, a dye that can colour cotton would usually not be appropriate for dyeing polyethylene, but by using a carbene, the same dye can be used for both. Carbene dye A carbene dye is a reactive dye based on carbene chemistry. A benzophenone is functionalised with a chromophore or group that can be easily converted to a chromophore at a later stage. The functionalised benzophenone is reacted with hydrazine hydrate and subsequently treatment with mercury oxide. The resulting diazo compound is stable at room temperature. On heating, nitrogen gas is released and the carbene generated. The thus generated