|The bluest aquamarines are called 'maxixe' (don't ask me how that is pronounced). Maxixes fade to white in sunlight or when heated.|
|Peridot can be found in some meteors.|
|Like many gems, topaz comes in a bewildering variety of colors. The rainbow-hued center specimen here is 'mystic topaz', which is colorless topaz that has been artifically treated.*|
*In my limited research it seems that a lot of modern gem stones are treated or irradiated to bring out a color they wouldn't have had in earlier periods of history. Unless you believe the Knights Templar knew how to use radiation. I don't have a reference handy but I've seen such claims in various kook books, usually following the old Ark of the Covenant and/or Emerald Tablet of Hermes Trimegistus as radioactive material/atomic reactor line of craziness.