Definition of "Crystal Form"?

Question

I need the definition for science.

Yeah, I know.

Sucks for me.

Thanks to all that help! :]

Answer 1

In chemistry, mineralogy, and materials science, a crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions.

The word crystal is a loan from the ancient Greek word κρύσταλλος (krustallos), which had the same meaning, but according to the ancient understanding of crystal. At root it means anything congealed by freezing, such as ice.[1] The word once referred particularly to quartz, or "rock crystal".

Most metals encountered in everyday life are polycrystals. Crystals are often symmetrically intergrown to form crystal twins.

Polymorphism is the ability of a solid to exist in more than one crystal form. For example, water ice is ordinarily found in the hexagonal form Ice Ih, but can also exist as the cubic Ice Ic, the rhombohedral ice II, and many other forms.

Amorphous phases are also possible with the same molecule, such as amorphous ice. In this case, the phenomenon is known as polyamorphism.

For pure chemical elements, polymorphism is known as allotropy. For example, diamond, graphite, and fullerenes are different allotropes of carbon.

Answer 2

When the bulk material has the same geometry of the fundamental crystal structure, it would be the crystal form.  Example would be quartz.  Quartz is a common mineral in many different rocks but, if you look at the rock, you do not see quartz crystals.  In a geode, the quartz forms in a space that allows the crystals to grow to some size without running into anything else.  People have found quartz crystals that are quite large.  hope this helps