THE COLOR OF MINERALS
Importance
Mineral identification
Main qualitative characteristic
Gems
Semi precious stones
provides information
Crystallochemical characteristics
Genetics of minerals
Caused by radioactivity
natural ionizing radiation
formation of color centers of electron holes
halite
fluorite
Quartz
calcite
Associated with transition metal ions
Emerald
Ruby
Rubelite
Rhodonite
Chrysolite
Metallic and covalent compounds
Native metals, sulfides and their analogues
Optical Interzonal Electron Transfers and Related Reflection Maxima
Metallic shades (Pyrite)
Metallic shades (Gold)
Fundamental absorption band
cinnabar
orpiment
cuprite
Distinction
Color of minerals
In individual crystals and mineral chunks
In thin sections
Transparent
In polished sections
In reflected light
Color of a mineral
streak
To describe the color
Comparative evaluation
with the color of some commonly known object or substance
Indigo blue
Green apple
Lemon yellow
Blood red
with "color standards" of minerals
Vermilion red
Emerald green
colors of metals or alloys
Tin white (Arsenopyrite)
Steel gray (molybdenite)
Brass yellow (chalcopyrite)
Copper red (native copper)
Methods continue to be developed
Three main groups
Idiochromic Minerals
Own color
Constant and predictable component
Blue azurite
red cinnabar
malachite green
Allochromatic Minerals
Other colors
Variable and unpredictable property
blue on Amazonite (orthoclase)
yellow in Heliodor (spodumene)
Rose on quartz
Impurities
Pseudochromatic Minerals
False colors
Variable color and unique mineral property
Precious opal
bright reflections of labradorite
between
Under the microscope
Impurities in the crystal lattice
Name: Karen Dayanna Molina Rincón
Class Name: Mineralogy and Crystallography
Mineral fine powder color
Another type of idiochromic mineral
electron transfers between different ions
trivalent iron ores
It is produced
When light is transmitted through a mineral
If it does not absorb any length
The mineral is colorless
Chromophores
Main chromophore elements
chromium (Cr)
iron (Fe)
manganese (Mn)
titanium (Ti)
cobalt (Co)
copper (Cu)