"Crystal" is a loose term, meaning anything that has a continuously repeating atomic structure. Ice is in fact a crystal.
All minerals form crystals. Different minerals require different environments to form. For example, diamond is a crystal of carbon, but needs extremely high pressures and temperatures found deep within the earth (~100km) to be able to crystalise. If the pressure is not high enough, it will form graphite, the dull gray material in a pencil.
Other minerals only form crystals at very low temperatures and pressures. For example, water ice (which is a mineral in its crystal form) must be at or below 0 degrees at 1 atmosphere, lower temperatures at higher pressures, to crystalise.
The slower a crystal forms, the "better" it will be. Large crystals with nice flat faces for example will usually only grow if allowed to do so very slowly with minimal physical disturbance.
Crystals
When crystals of dye are placed in water, they will dissolve if the dye is soluble. The dye molecules will disperse in the water, creating a colored solution. If the dye is insoluble, the crystals will remain visible in the water.
Healing crystals are mostly sold by them who deals in metaphysical crystals and its products like citrine, rose quartz, malachite and others. Online metaphysical stores are where you can buy these types of powerful crystals easily at good prices.
A snowflake can be made up of hundreds to thousands of individual ice crystals. These ice crystals form in a symmetrical pattern as they fall through the atmosphere, creating the intricate shapes we associate with snowflakes.
Crystals can be grown from borax and boiling water by creating a supersaturated solution of borax in the water. As the solution cools, borax particles start to come together and form crystals. By allowing the solution to sit undisturbed for a period of time, large borax crystals will begin to grow.
Yes, it is possible, in a humid environment.
The most calming color for creating a peaceful environment is typically considered to be blue.
You can eat some kinds of crystals... salt crystals and sugar crystals, for example. It's probably not a good idea to eat, say, quartz crystals, though.
Alum crystals typically grow better in a dark environment as light exposure can cause the crystals to degrade or discolor. It is important to store alum crystals in a dark place to maintain their quality and appearance.
Hypertonic environment.
The good kind. The more crystals, the better. The crystals are what get you high I believe
Sanitation, good housekeeping practices, harborage reduction, moisture reduction or creating a hostile environment in some cases.
Crystals
Amethyst crystals are known to turn into purple vapour when they are heated. This phenomena is due to the presence of iron impurities in the crystal structure of amethyst that react to heat by creating the purple coloring.
When crystals of dye are placed in water, they will dissolve if the dye is soluble. The dye molecules will disperse in the water, creating a colored solution. If the dye is insoluble, the crystals will remain visible in the water.
Water changes blue anhydrous copper sulphate crystals to white by creating hydrated copper sulphate, which is white in color.
Industry is somewhat helping. It is creating environment friendly products.