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Pink and green granite
Pink and green granite  
QUESTION: Hi, thanks for your time.
Could you please help me identify the minerals in my specimen? I found it in South Mississippi near the Pascagoula River.

ANSWER: Hi Tammy,
Unfortunately your picture is such poor quality that I cannot make out enough detail. Right now I can't even call this a granite or granitoid because I cannot make out distinct, visible minerals, inherent to a granite. If you can provide multiple picture, especially close-ups with higher resolution, that might help.
However, in general, the State of Mississippi is not known for actual large outcrops of plutonic igneous (such as granite) or metamorphic (such as gneiss) rocks. Igneous rocks are those rocks that either erupt on the surface of the earth by volcanic activity and then cool, which would make them very fine grained. Plutonic igneous rocks cool underground and make larger crystals, as in a granite. Metamorphic rocks are rocks that have been altered by immense heat and pressure. A gneiss is a coarse grained metamorphic rock showing larger crystals as well, often occurring in light and dark bands.
Thus your specimen is most likely a "transplant" from a distant area, arriving in Mississippi through ice transport during the last ice age. This is all I can tell you for right now.
Hope this helps a little.

---------- FOLLOW-UP ----------

South ms
South ms  

QUESTION: Thanks for your prompt answer! I live below the Chickasaway Formation. Here is, I hope, a better picture of similar smaller pegmatites. I'd like to know what their makeup might be.

Hi Tammy,
This is a little better. The picture labeled "Granite" is definitely a pegmatite (very coarse grained, usually granitic rock, with sometimes extremely large crystals). The pinkish material is most likely Potassium Feldspar (KAlSi3O8), the clear-milky material is quartz (SiO2), the small silvery flakes are Muscovite mica (KAl2(AlSi3O10)(F,OH)2). The blackish material is hard to distinguish from the picture. Possibilities are the mineral magnetite (Fe3O4) (see if a magnet sticks to it), or it could be hornblende ((Ca,Na)23(Mg,Fe,Al)5(Al,Si)8O22(OH,F)2), this is what I assume the larger black blob might be, or it could be black tourmaline, also known as schorl (Na(Fe32+)Al6(Si6O18)(BO3)3(OH)3(OH)), especially if it has an hexagonal outline, or if it is flaky it could be the black mica Biotite (K(Mg,Fe)3AlSi3O10(OH)2), or a combination of these.
The picture labeled "South ms" is still a puzzle, not enough detail to go on. The lighter colored band is probably a small microfracture filled most likely with quartz and some feldspar. The red color is probably some iron. Looks like it invades the greenish-black rock. However, this black-greenish part is still elusive. It could be some type of diabase (dolerite), a mafic igneous rock related to basalt and gabbro. It could be a dark metamorphic rock and with the greenish tint might be a greenschist, which contains greenish minerals such as chlorite, serpentine, green kyanite and/or epidote. But the picture still does not have enough resolution to say anything specific. These are just educated guesses.
Hope this helps a little more.


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Uwe Richard Kackstaetter, Ph.D. (Dr.K)


I can answer questions concerning minerals, mineralogy, gems, metals, groundwater, national and international geoscience field trips and anything that has to do with geology. As a public service and part as training for new geoscientists, our university department provides detailed FREE mineral identification for individuals with available non-destructive and destructive analytical procedures and a several page report. Please contact me for details or go to for details..


I am a professor of applied geology and mineralogy with many hours of field experience. Furthermore, I enjoy recreational gold prospecting and mineral collecting. As a professor I am engaged in research concerning minerals, their identification and their occurrence. I am currently developing inexpensive, accurate mineral identification procedures to be used by experts and lay people alike.

Member of the GPAA (Gold Prospectors Association of America) as well as the Association of Environmental Geochemists. Member of the GSA (Geologic Society of America) Member of the AIPG (American Institute of Professional Geologists)

Here is a small sampling: Mineral-rock handbook: Rapid-easy mineral-rock determination : written for anyone interested in minerals and rocks - Proctor, Peterson, and Kackstaetter;Macmillan Pub. Co. (New York and Toronto and New York) Physical Geology Laboratory e-Manual with 20 Lab Exercises [now available for FREE]: Colorado Front Range Self-Guided Geology Field Trips [FREE download] Kackstaetter, U.R. (2014): A Rapid, Inexpensive and Portable Field and Laboratory Method to Accurately Determine the Specific Gravity of Rocks and Minerals. The Professional Geologist, Vol. 51, No.2, AIPG. Kackstaetter, U.R. (2014): SEDMIN - Microsoft Excel (TM) spreadsheet for calculating fine-grained sedimentary rock mineralogy from bulk geochemical analysis. Cent. Eur. J. Geosci. DOI: 10.2478/s13533-012-0170-3

Ph.D. in Applied Geology and Mineralogy. I am actively teaching courses in mineralogy, igneous & metamorphic petrology, applied volcanology and a variety of national and international field courses with mineral collecting opportunities. Background in precious metal exploration and groundwater (hydrogeology).

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