Materia are small, round pieces of makou that can be used to cast “magic”.
One of the most commonly asked questions is how the color of materia can affect the power that materia has. Materia typically comes in five colors: green, blue, red, violet and yellow.
Green materia are the ones most people are familiar with. They are the most common, as you might guess from the fact that they are the natural color of makou. Green materia are the ones you find in everyday use: cure materia equipped to recovery units in the hospital, ice materia equipped to the refrigeration unit in the grocer’s store, and so on.
Blue materia take their color from the presence of additional oxygen in the crystal. This can result from either bubbles forming in the crystal or the presence of water, which can cause a slightly different crystalline pattern. The presence of this extra hydrogen disrupts the flow of normal spell energy that would otherwise be generated by the materia. Rather than having specific uses, they are “support” materia that can affect and enhance the energy of traditional materia.
Violet or “independent” materia carry energy that affects the user. They can enhance the natural energy field of any living thing, making one more or less attractive to animals, better able to manipulate energy, or more in tune with the atmosphere (which results in increased speed). The violet coloration results from the presence of iron derivatives such as manganese in the crystal. The heavy iron derivatives deflect the natural energy of the materia, flavoring it with the energy of the physical planet (as opposed to the metaphysical Lifestream of the Planet) and causing the materia’s effects to draw on the energy of the mundane earth instead of the spiritual one.
Yellow materia is considered the opposite of violet, allowing the bearer to affect others directly. This is why it is called “command” materia. Varieties of yellow materia have been know to give the owner the ability to learn things from the minds of others, confuse them, and even manipulate them. Yellow materia is strictly controlled for this reason. Its yellow color results from sulphurous impurities.
The materia we know the least about is the red materia. This materia can be used to “summon” various “spirits”. Each of these spirits has elemental affiliations not unlike the standard green materia. My theory is that each of these “spirits” is in fact an energy construct created by the Cetra in conjunction with the planet, much like the Weapons. Summon materia do not naturally result but are archaeological finds, produced by the Cetra in a process now lost, to store and release these constructs.
The “real” material that materia most resembles is the stone “quartz” and its variations. The number of variations quartz has is staggering: in two main divisions, it has dozens of varieties and includes everything from common stones like amethyst and citrine to substances like agate and varieties of petrified wood. Like different varieties of materia, the color and composition of various stones gives them different properties. Clear quartz, for example, is a “blank slate” used mostly for storing and directing energy. Amethyst, purple quartz, is said to promote clear thinking, restful sleep, and psychic powers. Rose quartz, a pink stone, promotes the love of others and of the self.
Of course, such things are considered “new age” science here, and attributed to superstition. The “magic” of materia is plainly obvious (as any randomly encountered monster will tell you) and rather than something to be debated, it is something to be studied.
So how exactly does materia work? Lifestream or makou is the closest thing that exists to pure energy in a liquid form. Materia, then, is solid energy. Natural materia forms a bond with its user, a tiny connection that is a much smaller scale version of the makou showers given to SOLDIERs. A small quantity of energy is absorbed through the skin of the owner and travels into the nervous system, joining the electrical impulses of nerves on the way to the brain. The connection between the user and the materia can be tenuous and even dangerous. The bodily energy required for a powerful spell can be significant, and if used without proper training can have the same effects of being struck by lightning – the energy drawn from the materia, given focus in the mind, and channeled back through the materia can literally burn someone’s nerves if they are not careful.
The artificial materia manufactured by Shinra Electric Power Company does not naturally create a bond with the user, and thus must be “equipped”. When plugged into a device with proper receptors – weapons, armor, and even some kinds of jewelry, all of which have electrode-like sensors against the skin – they can be used in ways similar to the natural materia for spellcasting. Other devices developed by Shinra allow them to function like batteries, giving off energy of the proper quality – an ice materia placed into an air conditioner takes the place of coolant, though the device itself must still be powered by an electrical current that keeps the materia activated constantly. (This process was originally developed by Phineas Shinra I using an electric power current to power a device using natural materia, but it’s much simpler today with the materia created for this purpose.) Because the artificial materia does not directly connect to the user, it is much safer to use.
There is a great difference, however, between the tiny exposure to makou that results from average materia use and the exposure of someone in the SOLDIER program. The introduction of nontrivial amounts of makou into the body has a number of effects, both obvious and not.
Source for Quartz: http://www.minerals.net/mineral/silicate/tecto/quartz/varietys/qrtzvary.htm
