Prasiolite: Montezuma

Montezuma prasiolite, also known as green amethyst, is a dazzling soft green gem created by introducing a special heating process to select amethyst or citrine gemstone.

The name prasiolite is derived from the Greek "prason" meaning leek-green colored and "lithos" meaning stone. This green form of quartz is the result of heating natural amethyst (purple quartz) or citrine (yellow quartz) to produce the desired golden green color. Other common names for this gemstone are vermarine, green amethyst or lime citrine. The range of colors and tones found in prasiolite vary from pale yellow green to deeper shades of green. Not all amethyst or citrine can be heated to produce prasiolite. Only a small percentage of these gemstones have the correct chemical composition to undergo the transformation. Premium quartz crystals from the Montezuma deposit in the Minas Gerais territory of Brazil produce the highest quality prasiolite when heated. The mining process for this gem involves a complex cut, often into large carats, to force the best color from the pale stone. Finished stones with dark green hues are considered the best quality. The color of this has been known to fade when exposed to strong sunlight, so store this gem away while tanning. This unique member of the quartz family is rarely found in retail stores. There are only a few companies in the world which possess the technology to coax this enticing green color from the stone. While prasiolite undergoes a unique heating process, heat treating in general is a common practice in the gemstone industry and does not compromise the value of the stone.