Chemical Formula: CaMg(CO3)2
Familly: Carbonates
Status: IMA-GP
Crystal System: Rhomboedric
Mineral for Display: Yes
UV Type | Main color | Intensity | Observation Frequency |
---|---|---|---|
Long Waves (365nm): | Yellowish White | Mid waves (320 nm): | Yellowish White | Short Waves (254 nm): | Yellowish White |
Other colors LW: | White , Bluish White , Pinkish White , Orange Red , Red , Violet red , Violet Pink , Pink , Greenish white , Yellowish , | ||
Other colors MW: | Pinkish White , Red , Violet red , Pink , | ||
Other colors SW: | Bluish White , Pinkish White , Orange Red , Red , Violet red , Violet Pink , Pink , Greenish white , |
Daylight Picture
DOLOMITE,
Horn Silver Mine, Beaver County, Utah, USA;
Photo and Copyright: James Horste
Used with permission of the author.
Short Waves Pictures (254nm)
DOLOMITE,UVSW
Horn Silver Mine, Beaver County, Utah, USA;
Photo and Copyright: James Horste
Used with permission of the author.
Galerie de photos:
...To the gallery (2 images in the gallery)
Triboluminescence: Yes
Thermoluminescence: Yes
The Crazy Calcite fluo red SW from Franklin, USA is sometime composed by dark red SW fluorescing Dolomite mixed with bright red SW fluorescing Calcite, with black Franklinite and tiny yellow Diopside crystals. The LW response is in shades of red-pink. It is however possible that the fluorescence of dolomite is due to the observation of the phenomenal fluorescence of calcite by transparency.
Most Common Activator: Mn2+
Other activators: Organic impurities , Ce3+ , Sm3+ , Dy3+ , Tb3+ , Gd3+ ,
Peaks in the spectrum (nm):
Mn2+I repl. Ca2+ : 578 - 582nm
Mn2+II repl. Mg2+ : 650 - 660nm
Ce3+: 360 - 370nm
Gd3+ : 312 nm
Tb3+ : 480, 545nm
Dy3+ : 478, 500, 572, 585nm
Eu3+ : 610 nm
Sm3+ : 560, 602, 645nm
[CO]n*? intr. : 410nm
ST: 475nm
530 (?)
The following emission centers have been found by steady-state spectroscopy: two different Mn2+ centers substituting for Ca2+ and Mg2+ and rare-earth elements such as Ce3+, Gd3+, Tb3+, Dy3+ and Sm3+ substituting for Ca2+ (Gorobets and Rogojine). Cathodoluminescence: Deconvolution of corrected CL spectra from dolomite shows two overlapping peaks at 17315 cm−1 (578 nm) and 15270 cm−1 (655 nm). In rare cases only the 655 nm Gaussian peak is present. The CL peak at 578nm (Ia) is due to Mn2+ in the Ca site and the peak at 655nm (Ib) to Mn2+ in the Mg position. The Mn2+ content in dolomite is linearly correlated with the normalized EPR areas of the two sites. The distribution ratio (KD) of Mn2+ in the two sites of dolomite, i.e. the Ca and the Mg position, was determined by EPR and CL spectroscopy. A linear correlation exists between KD from EPR and the intensity ratio IbIa from CL. CL spectroscopy is thus an appropriate method to determine KD in dolomite and evaporitic dolomites may be differentiated from non-evaporitic dolomites by their KD-values. (see: Mn2+-activated luminescence in dolomite, calcite and magnesite: quantitative determination of manganese and site distribution by EPR and CL spectroscopy, Ahmad El Ali et Al., Chemical Geology, Volume 104, Issues 1–4, 10 February 1993, Pages 189-202)
(*)Data are not exhaustive and are limited to the most important localities for fluorescence
Images:
http://www.mindat.org/show.php?name=Dolomite
http://webmineral.com/data/Dolomite.shtml
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