Answer:
if it gets lost or stolen the child will be far more sad than if it was a school material
Scientists can use the color of minerals to tell them apart.
Idiochromatic minerals <em>(self-colored) </em>due to their composition. The color is constant and predictable.
Allochromatic minerals <em>(other colored) </em>due to trace impurities or defects in their structure. The color is variable and unpredictable.
Pseudochromatic minerals <em>(false colored)</em> due to effects produced by light. The color is variable but a unique property of the mineral.