Ask A Scientist Chemistry Archive

status       student
age          7

Question -   Why do crystals shine?
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Michael,

When light lands on an object, the light can be either absorbed (soaked up) reflected (bounced 
off of) or transmitted (allowed to pass through) the object. Light that is reflected makes the 
crystals sparkle. Light that passes through the crystal is sometimes changed in color as it 
bounces around inside. That may account for the different colors you may see.

Regards,
ProfHoff 644
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Crystals are made up of really small things called atoms.  They are so small that you cannot
even see them with a microscope!  These atoms are put together in many different ways to make 
different kinds of crystals.  Some crystals do not look shiny.  Some look very shiny.  They look 
shiny because light reflects, or bounces, off of them.  If you shine a flashlight at a mirror, 
you can see the light bounce off the mirror.  With a crystal, light can bounce off the outside 
surface just like the flashlight on the mirror, or the
light can go inside the crystal and scatter in different directions or bounce around.  This 
depends in how the atoms were put together in the crystal. Many of these light rays bounce out 
of the crystal and you see the crystal as shiny or sparkly.

Pat Rowe
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