|How are pyrite and gold different? How do miners
tell the difference between "fool's gold" and
real gold? Which is more dense? pyrite or gold?
|Question Date: 2002-04-30|
Solids, liquids and gases are all made up of very
small particles called atoms. Each type of
given a name, and listed on the periodic
table. Some solids, liquids or gasses are
predominantly made up of only one type of atom.
Common examples would be aluminum, carbon (diamond
or graphite), and oxygen.
Gold is another
material that is predominantly made up of only one
type of atom, gold atoms. <
Pyrite is made
up of a combination of Iron and Sulfur atoms bound
together to form a compound (a compound is simply
a combination of different atoms bound
Though pyrite looks somewhat like gold, it is made
up of different atoms and has different
properties. For example pyrite is less dense,
harder, responds differently to heat and has a
different color than gold.
Pyrite is Iron sulfide, chemical formula FeS. One
of the quickest ways to tell that it is not really
gold is to try to draw with it on a piece of rough
porcelain. It looks lighter in color than real
gold, although without any real gold to compare
with, this is difficult to tell. However, if you
look at its "streak" - that is, the color it
writes when you draw with it on a "streak plate" -
a piece of white, rough, porcelain, you are in for
a surprise. It writes grayish-black instead of
gold or yellow when you try to draw with it! This
is one sure way to tell if you find pyrite in the
field, when you can't weigh it and test its
Gold is an element made of gold atoms. It
react easily with other elements. Like most metals
it is rather soft and shiny.
Pyrite is made up
of iron and sulfur and is one of the best known
minerals that are named "Fool's Gold" because only
a fool could believe they are gold! . Whether it
is the golden look or something else, pyrite is a
favorite among rock collectors. It can have a
beautiful luster and it is so common in the
earth's crust that it is found in almost every
possible environment, hence it has a vast number
of forms and varieties. Pyrite and Gold are easily
distinguishable. Gold is much softer and much
denser (gold is extremely heavy even for metallic
minerals)and has a different color than pyrite.
Pyrite is also more brittle and leaves a greenish
Pyrite is a mineral composed of iron and sulfur,
which happens to have a yellow luster that can
make it look like gold. Gold itself usually occurs
a sa native element (ie. gold on its own with
When you see the two
together the gold has a really bright canary
yellow color, while pyrite is a bronze sort of
yellow. They often occur together, as gold is
deposited in cracks in rocks by fluids (rocks
contain microscopic amounts of water), that
contain dissolved iron & sulfur.
sure how miners used to tell the difference, but
I've heard that they would heat up the pyrite,
which would turn the sulfur in it to hydrogen
sulfide, which is also known as 'rotten egg gas',
and very smelly! These days the pyrite/gold mix is
heated in a furnace to high temperatures and
dissolved in acid (gold does not dissolve in acid,
while pyrite does).
Gold is a lot more
dense than pyrite - it weighs about one and a half
times more than pyrite.
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