Meriden Mineral Club
Mineral Color
Mineral color can be subtle or intense. Many collectors gravitate to colorful minerals for obvious reasons. The following are examples of some minerals with spectacular color:
Amythest
Probably the most popular of the colored minerals is Amethyst. It is purple quartz colored by ferrous iron in the crystal lattice. Ferrous is the form of iron with a 2 + charge. It is an allochromatic mineral, colored by the iron impurity. The word lattice indicates that there is an organized arrangement of quartz molecules making up the crystal mass. Without the lattice organization we would not have the crystal shapes we see. As far as the purple color it has been said: "Ain't not nobody don't like purple!"
Turquoise
Most of us are familiar with Turquoise, that wonderful sky blue stone. Generally as cut stones in jewelry. However, as a mineral collector you can get decent rough which looks great in your collection or on your coffee table. This is a mineral whose composition gives the blue color. It's not from impurities. The term for this is idiochromatic.
Rhodochrosite
Another mineral remarkable for it vibrant pink color is Rhodochrosite. The best comes from Argentina. It has been called "Inca Rose". It is another idiochromatic mineral. It is a carbonate which was deposited in layers. You can see the oval rings with this specimen.
Lapis Lazuli
Another favorite for its color is the intense violet-blue stone called Lapis Lazuli. The only major massive sources of Lapis are Afghanistan and Chile. Insignificant amounts exist in a number of other locations. It is probably the "ultramarine blue" pigment used by Michael Angelo in his paintings. And it is safe to assume his source was Afghanistan.
Chrysoprase
Unbelievable Chrysoprase is a vibrant green chalcedony quartz colored by nickel oxide imputities. So it is another allochromatic mineral, colored by the nickel impurity. Chalcedony is the word for microcrystalline quartz, internally the crystal structure is too small to see. Chrysoprase is not very common, the best is from Australia. There is a good quality deposit in Tanzania also.
