Mineral Formulas & Compositions (as of 10/5/2003)

A big part of being able to understand mineral processes, and to think intelligently about rocks you come across is to understand the mineral compositions. For example, you might not be able to identify a mineral in a rock conclusively without lab tests (say, talc vs. pyrophyllite), but by knowing the other minerals in the rock and their compositions, you can make a good guess in the field (because phlogopite is present, it's probably talc, since both phlogopite and talc have Mg).

By the final exam, you should know the compositions and/or formulas for these minerals, and they will appear on the some quizzes as well. For those in which you are to know compositions only, I want you to know which elements or ions are in the structure, but not necessarily the relative amounts of each. For all the minerals you should also know the chemical group (e.g., borate, silicate, sulfide), the mineral group if it is a member of one (e.g., magnetite is a spinel, forsterite is an olivine, phlogopite is a biotite). For the silicates, you should also know the structural group (quartz is a framework silicate).

Mineral Identification

Of course, a big part of the course is learning to identify minerals. You must be able to identify all the minerals on the list below in "hand specimen," using only the standard tools (streak plate, scratch kit, acid, hand lens & your eyes/brain. For the most common rock-forming minerals, and a few others, you should also be able to identify them in thin section - these are indicated below.

Mineral Learn composition only? Identify in thin section? Learn Formula by End of Week:
Graphite
 
 
1
Sulfur
 
 
1
Chalcocite
 
 
1
Bornite
 
 
1
Galena
 
 
1
Sphalerite
 
 
1
Chalcopyrite
 
 
1
Stibnite
 
 
2
Pyrite
 
 
2
Molybdenite
 
 
2
Corundum
 
 
2
Hematite
 
 
2
Ilmenite
 
 
2
Magnetite
 
 
2
Rutile
 
 
3
Chromite
 
 
3
Goethite
 
 
3
Halite
 
 
3
Fluorite
 
Yes
3
Calcite
 
Yes
3
Siderite
 
 
3
Aragonite
 
 
4
Dolomite
 
 
4
Malachite
Yes
 
4
Azurite
Yes
 
4
Apatite
 
Yes
4
Barite
 
 
4
Gypsum
 
 
4
Forsterite
 
Yes
5
Almandine
 
Yes
5
Grossular
 
 
5
Zircon
 
Yes
5
Andalusite
 
 
5
Sillimanite
 
 
5
Kyanite
 
 
5
 
Mineral Learn composition only? Identify in thin section? Learn Formula by End of Week:
Topaz
Yes
 
6
Staurolite
Yes
Yes
6
Titanite
 
Yes
6
Epidote
Yes
Yes
6
Vesuvianite
Yes
 
6
Beryl
 
 
6
Cordierite
Yes
6
Tourmaline
Yes
Yes
6
Apatite
Yes
7
Enstatite
 
Yes 
7
Diopside
 
 
7
Augite
Yes
Yes
7
Jadeite
 
 
7
Wollastonite
 
 
7
Tremolite
 
Yes
7
Actinolite
 
Yes
8
Hornblende
Yes
Yes
8
Glaucophane
 
 
8
Serpentine
Yes
 
8
Kaolinite
Yes
 
8
Talc
 
 
8
Muscovite
 
Yes
8
Lepidolite
Yes
 
9
Biotite
 
Yes
9
Chlorite
Yes
Yes
9
Quartz
 
Yes
9
Cristobalite
 
 
9
Opal
 
 
9
Microcline
 
Yes
9
Orthoclase
 
Yes
10
Sanidine
 
Yes
10
Plagioclase
 
Yes
10
Nepheline
Yes
 
10
Sodalite
Yes
 
10
Stilbite
Yes
 
10
 
 
 

David M. Hirsch
Modified on Mon, Jul 12, 2004 at 11:14 PM