WHAT ARE CRYSTALS?
EVERY MOLECULE, HAS AN EXACT SHAPE,
WHETHER, THEY ARE LIQUIDS OR SOLIDS.
SCIENTISTS HAVE STUDIED, THEIR SHAPES,
WITH ELECTRON MICROSCOPES, FOR MANY YEARS
THOSE SCIENTISTS, DISCOVERED, THAT CHEMICALS,
NORMALLY HAVE, A SPECIFIC MOLECULAR FORM,
THAT THEY CAN OBSERVE, BY FREEZING THEM.
THE SPECIFIC MOLECULAR FORM, OF A CHEMICAL
IS CALLED, THE MOLECULAR CRYSTAL
OF THAT SPECIFIC CHEMICAL.
METALLURGISTS, ALSO HAVE DISCOVERED,
THAT METALS, AND MIXES OF METAL ALLOYS,
WHEN HEATED,TO THOUSANDS OF DEGREES,
DO NOT NORMALLY, MAKE THE SAME,
TYPE OF SMALL UNITARY MOLECULES,
THAT LIQUID CHEMICALS MAKE,
DIFFERENT SIZES
OF CUBIC CRYSTALS
BUT INSTEAD,  MAKE CONTINUOUS MOLECULES,
IN 3 DIRECTIONS, THAT ARE CALLED BY METALLURGISTS....CRYSTAL LATTICES.
BECAUSE THEIR NAMES, FOR THE CRYSTAL LATTICES,
SEEM TO BE SAYING, THAT THEY ARE, FOR SINGLE MOLECULES,
IUPAC'S COMMITTEE ON NAMES, MADE A SPECIAL SET OF NAMES
FOR THE SMALLER, SINGLE, UNITARY MOLECULES,
THAT NATURAL, ORGANIC AND INORGANIC, CHEMICALS HAVE.
THE NAMES, ARE SIMILAR, TO THE NAMES, USED BY THE METALLURGISTS,
BUT THEY ARE NOT, EXACTLY THE SAME,
BECAUSE, THE METALLURGISTS' NAMES, ARE FOR CONTINUOUS,
CRYSTALLIZED LATTICE, REPETITIVE 3-DIMENSIONAL STRUCTURES,
NOT FOR, SEPARATE MOLECULAR CRYSTALS.
THERE ARE ALSO VERY LARGE ROCK CRYSTALS,
THAT HAVE SIMILAR SHAPES AND SIMILAR NAMES,
THEY ARE MADE OF MILLIONS, OF SMALLER,
MICROSCOPIC SIZED, MOLECULAR CRYSTALS
THAT ARE DISCUSSED IN BOOKS ON MINERALOGY.
THE LONG, LARGE, SIX SIDED,
TAN QUARTZ, ROCK CRYSTALS,
THAT ARE GROUND INTO A FINE POWDER,
TO MAKE, SILICON CHIPS, USED IN COMPUTERS,
ARE AN EXAMPLE,OF THESE LARGE ROCK CRYSTALS.
ONE SMALL PIECE, OF THESE, QUARTZ ROCK CRYSTALS,
THE SIZE OF A PEANUT, HAS MORE THAN 23 MILLION,
SMALL, SIX-SILICON ATOM, HEXAGONAL CRYSTALS, IN IT,
THAT ARE ALL SEPARATE, MOLECULAR CRYSTALS,
THESE SMALL MOLECULAR CRYSTALS
ARE IMPORTANT TO CHEMISTS AND JEWELERS
BECAUSE THEY,  TEST BOTH,
GEMS & CHEMICALS WITH EQUIPMENT,
THAT MEASURES THEIR SIZE, WEIGHT
AND THEIR LIGHT REFLECTANCE.

EACH OF THE PAGES, OF THIS LESSON SHOW,
THE DIFFERENT TYPES OF MOLECULAR CRYSTALS,
A HEXAGONAL QUARTZ
SILICATE CRYSTAL
THAT SCIENTISTS, HAVE RECENTLY DISCOVERED,
WITH SCANNING TUNNELING, ELECTRON MICROSCOPES.
WE SUGGEST YOU START WITH,
THE SIMPLE CUBIC SHAPED MOLECULAR CRYSTALS
AND WE ARE SURE, THAT ONCE, YOU HAVE LOOKED AT THE CUBIC CRYSTALS,
YOU WILL FIND, ALL THE OTHER TYPES OF CRYSTALS,
VERY EASY, TO COMPREHEND.