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Question
Peg1
Peg1  

Peg2
Peg2  
Hi, could you help me identify the minerals in these rocks? I found them both in the same place, but they are very different. I live South of the Citronelle Formation. Thanks for your time.

Answer
Peg 1 - I can not see all of the minerals from the photo very well but it appears to contain AT LEAST quartz SiO2 (the clear glass looking mineral), feldspar mineral(s) - I can not tell for sure which, there are six or seven different feldspar minerals but there appears to be more than one, and probably hornblende.  Hornblende is a group name used to describe Ferro-hornblende and Magnesio-hornblende, but the term is generally more inclusive for all calcium aluminum amphiboles. (Hornblende is frequently also used to describe any dark, opaque amphibole mineral without individual analysis which is the case here.) The individual Hornblende minerals appear very similar and can be virtually indistinguishable without complex analysis, and are often just grouped under a Hornblende label without further distinguishing.

The Peg 2 - is much easier and appears to be orthoclase (a feldspar); copy and paste the below and compare it with yours; I can not see the twining in your picture but I would suspect that you can see it if you look hard.  Orthoclase always has twinning.

https://www.google.com/search?q=orthoclase&biw=1280&bih=685&noj=1&tbm=isch&imgil=6zqI2MMckjczyM%253A%253BPDlgmsKOMputtM%253Bhttp%25253A%25252F%25252Fskywalker.cochise.edu%25252Fwellerr%25252Fmineral%25252Forthoclase%25252ForthoclaseL.htm&source=iu&pf=m&fir=6zqI2MMckjczyM%253A%252CPDlgmsKOMputtM%252C_&usg=__-FNnq67Y-OELzbl_gEApynQxo7E%3D&ved=0ahUKEwj34uie7vnNAhXCFZoKHUudArEQyjcIlQE&ei=YSSLV7euBMKr6ATLuoqICw#imgrc=6zqI2MMckjczyM%3A

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Joe Norris

Expertise

I am an economic geologist. An economic geologist does mineral evaluations and appraisals of mineral or mining properties. I can tell you if your deposit has value - remember that a mineral deposit, no matter how good, only has value when mined. Any value assigned to a mineral deposit, in the ground, is only the speculative value that deposit.

Experience

I have been a economic geologist for most of my 35 year career. Although I have done work in perhaps 45 states and numerious countries much of my work has been in Appalachian coal, intermountain west gold and silver, and Arizona uranium.

Organizations
Past President of the Virginia Section of the American Institute of Professional Geologists and a certified geologist in twelve states.

Education/Credentials
BS Degree from Eastern Kentucky University. Work on MS Degree @ Eastern Kentucky University, Colorad School of Mines & Marshall University Numerious short courses on the value of mineral deposits and how to value same. Also several short courses dealing with the different types of geologic processes; sedimentary, igneous, metamorphic along with the mineral associated with each.

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