### stone:

Lapis lazuli
* are minerals
* contains the minerals calcite, pyrite , and sodalite.
* dark blue stone used as a decoration and as a gemstone.
* is mined at the deposits of the ancient world in Afghanistan
  - one of the few important rocks for beads
  - perhaps the most well-known rock commonly encountered in the gem world
  - sensitive to strong pressure and high temperatures

### stone:

Metamorphic rock
* All metamorphic rocks have one thing in common, time.
* Many metamorphic rocks contain large and beautiful crystals.
* are VERY uncommon in Iowa
  - almost always harder than sedimentary rocks
  - complex
* are formed by rocks coming under great pressure and high temperatures
  - when great heat and pressure change other rocks
  - often very hard and resistant
  - rare in Kansas
  - records of heat flow through the orogen
* are rocks formed by the alteration of preexisting rocks deep within the Earth
  - that have been changed by heat or pressure while forming
  - stones
* are the result of the dynamic nature of our Earth
  - third great class of rocks
  - wrought from the altera- tion of other rocks
* begin as either igneous rocks or sedimentary rocks.
* can be themselves metamorphosed or remetamorphosed.
* can begin as igneous, sedimentary or other metamorphic rocks
  - sedimentary, igneous or metamorphic
* can change with heat and pressure
  - without melting
* can form from either sedimentary or igneous rocks
  - preexisting metamorphic rocks
* change in the solid state by replacement or rearrangement of molecules.
* come from all types of rock, igneous, sedimentary and metamorphic rocks
  - in a poor third
* form at depths of a few to many kilometers below the Earth's surface
  - high pressure and temperature by causing new minerals to grow
  - only by an increase in temperature
* tend to break or cleave most easily along planes parallel with foliation
  - have higher density than the original rock due to pressure and heat
* yield water in substantial quantities only where they have been fractured.
+ Rock (geology), Rock classification, Metamorphic rock
  * Metamorphic rocks are formed by rocks coming under great pressure and high temperatures. These temperatures and pressures are found under mountains and volcanoes, especially when continental plates move together. These conditions change the make-up of the original minerals.

### stone | metamorphic rock:

Schist
* Most schists are mica schists , but graphite and chlorite schists are also common
  - schists, but graphite and chlorite schists are also common.
  * Most schists have been derived from clays and muds which have passed through a series of metamorphic processes involving the production of shales, slates and phyllites as intermediate steps. Certain schists have been derived from fine-grained igneous rocks such as basalts and tuffs. Most schists are mica schists, but graphite and chlorite schists are also common
* are foliated rocks that are primarily composed of lamellar minerals such as micas
  - rocks that can be split into thin plates
* have the quality of breaking off in thin, wavy layers.

Outcrop
* are places where solid rock is exposed at the surface
  - the visible parts of the rock formation that makes up an area
  - usually sparsely vegetated, and occur on slopes and tops of low hills
* provide information about the type of rock or sediment underlying an area.

Pigment stone
* are often radiopaque and can be seen on plain abdominal x-rays.
* are small, dark stones made of bilirubin and calcium salts that are found in bile

Pink stone
* bring peace, happiness, joy, and laughter.
* promote peace, happiness, joy and laughter.

Precious coral
* is red and branching, found in the Mediterranean.
* species valued for jewelry.

Pumice stone
* operates like lava but collects less residue.
* work well to knock off the heads of black algae.