It can be combined with different materials such as glass , plastic, wood , metal, etc. Fractions can be stringed on wire or eyepin and then hang on a chain .
No. 19 is colored stone, which may dye in contact with skin.
No. 6 can have color tan and pattern , it is a natural material and as such may have the size , color and shape variations !
No. 30 is fractional carnelian.