I need answers for following questions as below:
-1 How Diamond and Graphite's different structure impact their perceived colour?
-2 If malachite and azurite are so closely related chemically, why do their colours differ so much?
-3 Why to the fluoresced colours of the above minerals differ?
-4 What type of silicate is made from sheets of silicate tetrahedra? Give an example. Are these silicates brittle or strong?