This comes from the Greek
word "anthrax", meaning "coal." Anthracite is commonly referred to as "hard
coal." In the United States, anthracite is mined mostly in eastern Pennsylvania.
BIOTITE
This mineral is named after
the French physicist Biot, who lived from 1774 to 1862. It is a kind of
mica, often called "black mica." Large sheets of biotite were once used
as heat-resistant windows on ovens and furnaces.
CALCITE and CHALK
These are very closely related.
Both names come from the Latin word "calx", meaning "lime." Calcite is
a very common mineral. Clear calcite is used in special kinds of microscopes.
FELDSPAR
This name comes from the
German word for "field" and "clip of wood." Feldspars are the most common
of all minerals. Certain kinds are used in glass making, while others are
set in jewelry.
GALENA
This is the word the Greeks
used for a kind of lead ore. To the Romans, galena was what was left after
the lead was melted out of the ore. Galena is the ore from which we get
most of our lead.
GRAPHITE
This comes from the Greek
word that means "to write." Graphite is the "lead" in pencils.
HEMATITE
This comes from the Greek
word for "blood", "haima." Hematite is the ore from which we get most of
our iron.
LIMESTONE
The word "lime" is related
to a lot of other words-an old Greek word meaning "a moist meadow", Latin
words meaning "mud" or "slime", and an Old English word "loam." There are
many different kinds of limestone. Some of them have been used for hundreds
of years to make cement and plaster. There is no connection between this
word "lime" and the name for the green fruit. That "lime" comes from the
same root as the Arabic word "laimun", which means both "lemon" and "lime."
MAGENETITE
There is a place in ancient
Greece called Magnesia. Magnets were first found there, and they were named
"the Magnesian stone." Magnetite is a mineral that contains a great deal
of iron and is strongly attracted to magnets; hence, its name.
MARBLE
This name comes from the
Greek word "marmaros", which means "shining stone." Marble is a metamorphic
rock, formed naturally from limestone that is under great heat and pressure
over a long period of time. It is often used as a building stone.
OBSIDIAN
This comes from the name
of a man, Obsius, who was supposed to have found this rock in Ethiopia
thousands of years ago. Obsidian is ancient volcanic glass and was once
widely used for arrowheads.
PUMICE
This volcanic rock was called
pumax by the Romans. The name is related to their word for form, "spuma."
Pumice is used for polishing hard things.
QUARTZ
This stems from the German
word for "quartz"-"Quarz." Nobody seems to know where the German word came
from. Quartz is an abundant mineral. Most sand is made up of small pieces
of quartz. Quartz is important in glass making and in electronics. It is
also used for sanding hard surfaces.
SANDSTONE
Sandstone is a sedimentary
rock composed mostly of quartz grains cemented together. It is used as
a building stone.
SHALE
This is related to the word
"scale", as in "fish scales", because shale occurs in flat layers. The
name comes from an old German word meaning "shell." Shale is sedimentary
rock; that is, it is formed from layers of mud which have been under pressure
for a long time.
SLATE
This comes from the Old
French word "esclat", meaning "splinter" or "slat." Slate is a metamorphic
rock formed from shale under great pressure. It is used for chalkboards
and as a building stone.
TALC
This word comes from the
Latin word "talcum." In Old French, talc meant "mica", probably because
some forms of talc occur in thin layers or plates like true mica. Talc
is commonly used in talcum powder.
