Cross Stone (Chiastolite) Ring Beach Glass and is therefore moderately hard

and is therefore moderately hard and suitable for most types of jewelry

the color variations are caused by various impurities

which is also much rare than Rubies making it highly desirable

with less common reddish-browns and yellows

including blue

Cross Stone (Chiastolite) Ring Beach Glass and is therefore moderately hardCross Stone Ring Size: 8 Length: 15 16" Width: 5 8" Chiastolite, also known as Cross Stone, is a very rare variety of Andalusite, an aluminum nesosilicate mineral with crossed shaped inclusions of black Graphite and Carbon. The cross can only be seen when this mineral is sliced, though it does run throughout the entire stone.