Herkimer diamonds aren't diamonds. They're quartz formations
which, because of their brilliance and diamond shape have
been given that name. As for the Herkimer part, they are
mined only in Herkimer, NY (although in recent years miners
in Oaxaca, Mexico and other parts of the world have found
quartz similar in shape to Herkimer's).
In crystal layouts Herkimer diamonds are probably the most
effective crystals to use to release energy blockages. They're
particularly helpful when placed between chakras. For example,
if you had difficulty in communicating with someone you
loved and this difficulty was affecting the quality of your
love, you might place a Herkimer between the heart and throat.
A Herkimer diamond, like all forms of clear quartz, will
enhance the energy of any crystal it is placed with in a
crystal layout.
Because of its ability to help release energy blockages,
which often express themselves in the form of stress and
tension.
One of the most striking aspects of Herkimer diamonds is
their ability to enhance dream recall. If you have difficulty
remembering your dreams or aren't even sure that you have
them, this is the most likely stone to help.
However, some people find their dreams becoming so vivid
that they feel as if they weren't asleep at all. There is
a solution to this problem. When an amethyst is placed with
the Herkimer, the latter's energy is softened. You will
still clearly remember dreams, but will feel rested.
One last quality of Herkimer diamonds is that they seem
to have the ability to raise human energy levels, and are
thus recommended whenever you need more cheer in your life.