Originally Posted by
thebigspendur
It just refers to the form the xtls take. All minerals in the world are found in their respective xtl systems defined by their symmetry meaning the ratio of the lengths of the sides and the angles where the sides meet. Symmetry runs from highest to lowest and each system has a textbook perfect form but in nature the xtls are oftentimes combinations and they are oftentimes deformed: cubic, tetragonal, orthorhombic, hexagonal, monoclinic and triclinic. Garnets are in the cubic system and are usually found as dodecahedrons but can be found several other ways. You can find single garnet xtls hundreds of pounds and also microscopic. Those tiny ones are the ones we are concerned with however depending on whether its garnet made of calcium, iron,chrome,magnesium and a bunch or others will help determine the actual hardness of the garnet.
All this stuff is actually mineralogy which is different than geology. Call a mineralogist a geologist and he'll punch you in the nose. Its a lot of physics and chemistry. Mineralogists use x-ray defractors to analyze the inner workings of the xtls and their lattice structure and I think I'll stop here before I confuse you anymore because this stuff gets real complicated and really means nothing to us shavers.