Hopper and Skeletal Herkimer Diamonds
Best Website for Herkimer Diamond Information - Made Possible by Collector Donations
The information, and photography, on this website is copyright protected
by W. David Hoisington, Ph. D. unless another author/photographer is cited.
Welcome to the New Herkimer Diamond Story!
Return often and follow this developing story. Refresh your
browser (right click) to see new updates
These odd looking quartz crystals from the Herkimer mining district are found in every deposit. They
have an important message to share with us about the growing environment for Herkimer diamonds..
The Significance of
The slide show starts with a slde of “examples of
hopper growth”. These are NOT from the Herkimer
district (the sldes after will be!). They are shown to
share with the viewer images which might be
familiar. Also, knowing that the conditions which
make hopper crystals can be seen in other minerals
helps us to understand the processes.
There is a photo of hopper salt crystals. These are
formed when the water evaporated rapidly thus
increasing the salt content dissolved in the water
(called salinity). When the conditions are right, the
solutions will get to the point where the salt can no
longer stay dissolved. That is when crystals will
begin to form and then grow. Most authors speak
about saturation (amount of quartz dissolved in
solution) at very high levels (called super saturation)
as being the governing factor for hopper type growth.
But in the Herkimer district it is likely the
hydrocarbons and kinetic energy, also played a role.
In the slide are illustrations of how hopper and
skeletal crystals were formed - its a competition
between crystallization on the edge versus on the
face. The presence of hopper growth patterns is
indicative of rapid growth rate. The slide show
contains many different features seen in association
with hopper development across the Herkimer Mining
Terminology Several different terms are applied by collectors to this form of Herkimer diamond - elestial, jacare
quartz, negative manifestation quartz, skeletal, negative skeletal quartz, fenester quartz, window quartz, cavernous
quartz and hopper. In the mineral kingdom the term “skeleton” frequently refers to the process of solving the crystal and
leaving a skeleton behind, although the shape of a full hopper looks quite similar. Skeletal is the term most commonly
used in labeling Herkimer diamonds with any hint of hopper step like growth. It may not be the proper term. A more
appropriate label would be “Herkimer diamond with hopper growth”. If the growth is preserved inside the crystal, and
you can see it, then “Herkimer diamond with window to hopper growth”. The window can be described in the label as
open, partial, or closed. The labeling is further complicated by over growths, secondary event features, spiral
tendencies, and parallel growth all contributing to complex hopper growth.
Slide show contributors:Example Name……
The new discovery, to be
announced on July 16 and 17, will
change how we understand
hopper growth in the Herkimer
Contribute to Herkimer
Diamond research and
have your name below!
Thank you Shannon Haley
Wilbur for the donation of 30
samples from the Fonda
region.1/05/2019 and 3/2/2019
Check out her Facebook.