As a girlie girl who likes gem stones and semi-precious stones simply because they are sparkly and pretty, I have found in the past that it’s surprisingly difficult to find girlie girl level info on a certain gem, all in the one place.
So, as no one else seems to have put birth stone, zodiac stone, anniversary stone, symbols and meanings, energies, planets, and other "proper" info like where they come from, hardness, chemical make up and so on altogther, I thought I would do it. I must stress that my Gem Info Pages are definitely not what you need if you are writing a thesis on a gem, or are some kind of gem type boffin. They contain the info that I always want when buying a gem as a gift. It is girlie gem info…with some science stuff thrown in at the end.
But first, for those of us who do not have a degree in Gem terminology, here is a quick dictionary type thing explaining some of the weirder words you might come across in my Gem Info Pages.
CRYSTAL SYSTEM
This is the structural shape of the gem – the way the crystal forms. There are 7 different forms, each with a fancy name:
Isometric
Tetragonal
Hexagonal
Trigonal
Orthorhombic
Monoclinic
Triclinic
The explanations of each name are all to do with maths, angles and "planes" and mean nothing without complicated drawings, so I am not including these. Generally speaking, these are not things you need to know when being girlie about gems.
HARDNESS
This is measured using the Mohs Scale, invented by German mineralogist Friedrich Mohs. He placed 10 minerals in a scale so that each could only be scratched by those above it and in turn could scratch all those below it:
1......talc......................... powered by fingernail
2......gypsum................. scratched by fingernail
3......calcite.................... scratched by copper coin
4......fluorspar............... scratched by pen knife
5......apatite................... only just scratched by pen knife
6......orthoclase............. scratched by steel file
7......quartz.................... scratches glass
8......topaz...................... scratches quartz
9......corundum............. scratches topaz
10....diamond............... cannot be scratched
CLEAVAGE
This is the term for whether or not a gem will break smoothly and evenly along one surface or "plane" – some do, some don’t and some are in the middle.
FRACTURE
Some Gems break very distinctively when hit or smashed and these patterns have names:
conchoidal................... shell like
subconchoidal............. indistinct shell like
even............................. flat surface but slightly rough to the touch
uneven........................ rough and irregular
hacky........................... with sharp points
earthy......................... dull and crumbly
LUSTRE
This describes the way light bounces of the surface of the gem. The different ways have different names:
Metallic................................. like polished metal
Adamantine......................... brilliant, like diamond
Vitreous................................ like broken glass
Resinous............................... like resin or wax
Pearly/silky/splendent.......... brilliantly reflective
Shining.................................. reflective but not mirror
Glistening............................. reflects light not images
Glimmering.......................... imperfect reflections from points
SPECIFIC GRAVITY
This is the weight of the gem compared with an equal volume of water. This is used as similar sized but different gems can vary in weight enormously.