Why most mineral samples do not visibly demonstrate their chrystal form??

Question

Why most mineral samples do not visibly demonstrate their chrystal form??

Answer 1

Minerals do show there crystal form, you need to look at a website called Mindat where there are thousands of pictures, for example the mineral Celestine is used in fireworks, Copper is widely used ...

Answer 2

Because they have crystallised in a confined space, locked between other minerals in solid rock.  Larger crystals need space and time to grow, such as in a hollow or vessicle.  However, a mineral grain will still show its crystal structure, and under a microscope, it can be identified because of its distinguishing characteristics.

Answer 3

Minerals are usually mined not on its purest form. Impurities changes the color, structure and characteristics of the minerals. That is why in mining recrystallization is one of the process to eliminate impurities.

Answer 4

I do not believe that is really true.  At least  not in my experience.  I admit that it is rare to see minerals in a nice crystal structure, a euhedral mineral, but the general crystal structure is apparent in most minerals in their natural condition.

There are many reasons why minerals are not usually found in a nicely formed crystal, mostly it is a question of competition for space (other minerals interfere with the growth) , insufficient time for the mineral to form in a good structure (the atoms freeze into place faster than a perfect mineral can form), the presence of impurities disrupting the structure, and just the random nature of how atoms move around.