Have you ever wondered how your Gemstone gets it’s color? There are three main ways Gemstones get their color; being Idiochromatic, Allochromatic, and Pleochroic.
Idiochromatic is a Gem whose coloring element is vital for the making of the Gem. Confusing? I’ll put it this way; lets say we’re making corn bread, the finished bread is yellow, right? Why? because the corn is the “element” that colors it yellow! take out the corn, and it is no longer corn bread! That makes the corn a vital element, also making the corn bread “Idiochromatic”. The same with Peridot, (which is Idiochromatic) Iron colors it green, but without Iron it would no longer be Peridot!
Allochromatic is a Gem whose coloring element is not vital for the making of the Gem. Let’s say we’re making a birthday cake, the finished cake is plain white, but what if we add red food coloring? We now have a red birthday cake! Take out the coloring and you still have a birthday cake! The same with Corundum, chromium and iron make it a red Ruby, but without the coloring it is still Corundum! (Though a clear piece of Corundum) That makes both Corundum and the “birthday cake” Allochromatic.
Pleochroic is a Gem that gets it’s coloring from white light splitting into it’s prisms, in other words, different colors when viewed from different directions; Opal is Pleochroic because when the Atoms inside grow, they arrange themselves in different patterns; therefore splitting the light into rainbow colors.