Oligoclase is a rock-forming mineral belonging to the plagioclase feldspars. The Mohs hardness is 6-6.5 and the specific gravity is 2.64-2.66. In color it is usually white, with shades of grey, green, or red.
Imitation Rhodium uses a similar-looking material to substitute for rhodium. It makes the jewelry more affordable, but at the same time keeps the same appearance and quality as a rhodium coating.