### substance | mineral:

Feldspar
* All feldspars contain alumina and silica
  - have two cleavage directions
* act as a flux to melt the silica into a licquid glass.
* also contain potassium which major nutrient for plant growth
  - occur in the silt-sized fraction of most mudstones, but in very small amounts
* are aluminum-rich silicate minerals that are very common in rocks like granite
  - mostly orthoclase and microcline with very little plagioclase
  - normally light-colored, including pink, white, tan, gray or green
  - relatively scarce, whereas quartz, muscovite, chert, and rock fragments are abundant
  - the most abundant minerals in the earth s crust
* are the most common minerals in the Earth's crust
  - of all minerals
  - commonly observed minerals in soils that are twinned
  - principal components of igneous rocks
  - usually colorless in thin section, have low relief and lack pleochroism
* are, in general, the most abundant minerals that occur in igneous rocks.
* change to clay, metals dissolve in water.
* contain silica, alumina , and fluxes.
* have particularly interesting effects with light.
* range in color from clear white or gray to shades of blue, green, or pink.
* show both a grain-shape fabric and biotite, a pervasive foliation.
* turn out to be the most common minerals in the Earth's crust.
* weather progressively to kaolinite and amphiboles to smectite
  - to yield a large part of the clay found in soils

### substance | mineral | feldspar:

Potassium feldspar
* are highly dissolved and are altering to kaolinite.
* contain considerable potassium.

Fluorite
* Most fluorites have characteristics
  - optical characteristics
* Some fluorite is colored violet in contact with arsenides
  - violet at the contacts with nickel arsenides
* use goes back thousands of years.

Fluorspar
* continues to be extracted on a commercial basis.
* fluoresces brightly.
* is mined nowhere else in the United States.
  - composed of calcium and fluorine
* source of hydrofluoric acid used in many industrial applications.

### substance | mineral:

Garnet
* All garnets have almost identical atomic structures
  - basically the same structure, but different chemical compositions
* Most garnet is used as an industrial abrasive, but occasionally gem quality stones are found
  - garnets are red in color, but they display some variety
* Some garnets also exhibit color change and stars.
* Some garnets have central turbid areas
  - no identifiable species and are called just a garnet
* actually sweep across all colours except blue.
* also come in stunning shades of green, orange and gold.
* are a basic for the businesswoman's wardrobe
  - also an important symbol of fidelity, faithfulness and protection
  - from brownish, purplish reds, blood-red, oranges and greens and colorless
  - glassy red , pink or reddish brown
  - isostructural , meaning that they share the same crystal structure
  - rare in igneous rocks
  - shown in magenta, staurolite is blue and plagioclase porphyroblasts are light yellow
  - silicate minerals which occur in all colors except blue
  - usually formed by metamorphism, however some have igneous origins
* belong to the isometric crystal class, which produces very symmetrical, cube-based crystals.
* can occur in every color except for blue.
* differ extensively in chemical composition from each other.
* endow the wearer the ability to make deep and lasting friendships.
* form in the cubic system.
* is precious stones
* occur worldwide in a variety of rocks, particularly gneisses and schists.
* occurs in rounded grains, has very high relief in plane light and is isotropic.
* protect travelers, prevent fever, and promote good health.
* sharpen self-perception and extend openness to others.