In isotropic (having a physical property which has the same value when measured in different directions) use a glass material and carefully examine this description when glass is broken and forms fragments.
Extensive properties, such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance's chemical identity.
For glass even the broken pieces will have same reflactive index