You are given two crystals. One crystal is a diamond and the other crystal is a cubic zirconium. Both are virtually the same hardness. What simple

You are given two crystals. One crystal is a diamond and the other crystal is a cubic zirconium. Both are virtually the same hardness. What simple test could you perform to tell them apart? What does the hardness and "perfect" cleavage suggest about the bonding in these crystals? What mineral group would a diamond be classified as? What mineral group would a cubic zirconium be classified as (why is that a trick question)? Lastly, would you settle for a blue cubic zirconium rather than a blue diamond? Defend your reasoning.