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DICTIONARY
Dictionary
Use this list of commonly used words in the mineral collecting world to further your knowledge and understanding.
Fleabites, Ratbites, Wilbers, & Dings
Terms used to describe very small points of damage on a crystal. These terms all describe little chips that seem to be missing from the specimen's termination or edge, and often appear as if the piece was "bitten" by a flea or rat. The term "Wilbers" is derived from a legendary mineral collector, Dave P. Wilber, who is known for his strict standards for the condition of a specimen. See diagram below for example.
Cleave
The tendency of a mineral to break along smooth, flat planes, which are determined by the arrangement of atoms and ions within the mineral's crystal structure. If bonds in certain directions are weaker than others, the crystal will tend to split along the weakly bonded planes. See diagram below for example.
Break or Damage
Points on a specimen that are broken, typically in random and unpredictable places with no patterning or structure. This can happen in situ (in the ground), during the extraction process, or after the specimen has been collected due to human error. See diagram below for example.
Edgewear
Also known as "Chattering", the term used to describe multiple "Dings", "Fleabites", "Ratbites", or "Wilbers" along the edge of a crystal. See diagram below for example.
Internal Fracture
When a specimen shows cracks or cleaves that are inside of the crystal itself. Typically this is the result of thermal related damage.
Inclusion
Impurities within a crystal such as dirt, sediment, other minerals, remnants of matrix, or even other crystals.
Restoration
When a specimen was damaged, and a lab uses a color, clarity and texture matching epoxy to restore the crystal to the way it once was. Restorations are invisible to most naked eyes, and can be revealed with a UV light.
Repair
When a crystal was broken, and is put back together using a low viscosity bonding that is nearly invisible to the naked eye, but can be revealed with a UV light.
Damage
There are many types of damage that can be exhibited on a mineral specimen. Additionally, there are examples where multiple names represent the same type of damage. An example of this is Fleabites, Ratbites, Wilbers and Dings all represent the same thing; very small areas of damaged where a part of the crystal is missing.
Pristine
Cleave
"Ding"
"Wilber"
Edgewear
Break
Please note the damage exhibited in this photograph is not actually present on the real specimen; it has been digitally edited for educational purposes.
Termination
All crystallized mineral specimens terminate in some form or another. Sometimes a termination can be a point, flat edge, cube, or octahedron. Other times a termination(s) can be multiple small peaks or even spheres (Botryoidal). Terminations vary in appearance depending species, localities, and crystal systems.
Terminations
Terminated Crystal
Matrix
The "host rock" of the main crystal, or the material in which a crystal or fossil is embedded in or on. A matrix can be a crystallized, single mineral, or a compound of multiple minerals.
Matrix
Main Crystal
Matrix
Main Crystals
C-Axis
One of the three imaginary lines or crystallographic axes used to describe the internal structure and symmetry of a crystal, also known as the vertical axis or the axis of highest symmetry. The C-Axis often is the most commonly recognized and appreciated axis, as it typically reveals the richest coloration of the crystal.
C-Axis
C-Axis
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