The Amethyst Aegis is a rare type of shield. The body of the shield appears to be made entirely of one giant cut crystal of Amethyst, the facets of which appear to sparkle when it is rotated. This is capped with decorative golden metal at the corners of the shield and at the center of the front of the shield.
The entire crystal is tinted by dye except for the golden metallic regions. It will dye to an inverse of the color applied (with the exception of silver, white and black dyes) but this will only show in only some facets of the crystal - which facets appear tinted depends on the viewing angle; some facets will always retain their magenta coloring at any given viewing angle. It seems to be dyed yellow by default.
Other shields with this appearance: