Genuine Gems and Minute Minerals
Minerals
Some rocks are
made of just one mineral, while others are made
of several different minerals. Maybe as many as
a dozen! About 98% of the rocks in the crust of
the Earth are made of silicate minerals, which
contain oxygen and silica. Geologists classify minerals
into silicates and nonsilicates.
A mineral can be
identifyed by it's color, fracture, cleavage,
luster streak of the mark it leaves, desting, hardness,
and how it reacts with acids.
Gems
The world around us is made of tiny crystals. Much of the
surface of the Earth is made of rocks that have minerals
in them. These are formed from crystalline particles.
What is a crystal?
Sedimentary
Igneous
Metamorphic
Rocks and Minerals
The Earth, Yesterday, Today, and Forever