Phosphorus has all sorts of allotropes (different physical forms of the same element), which come in many colors: Red, black, and white being the only real ones (and white being the most dangerous by far). Violet phosphorus is a mixture of the red and black allotropes, quite unusual, and it was made by Max Whitby himself using one of the strange recipes of heat, pressure, and catalysts needed to transform phosphorus among its various crystal structures.
I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.
Source: Max Whitby of RGB
Contributor: Max Whitby of RGB
Acquired: 15 May, 2005
Text Updated: 4 May, 2007