There are no exacting standards to determine the value of minerals. An experienced person can guess a specimens price range by gathering certain information about the specimen. Certain unique properties will set it aside from other specimens of the same type. The important properties are:

• color and intensity of color
• transparency
• luster
• formation of crystals
• size
• anomalies
• presence of a matrix
• demand
• rarity

Color and Intensity
A specimen with a dull color does not stand out. Intense colors quickly grab the eye and raise the value of a specimen. Rhodochrosite from Alma, Colorado, is very costly, primarily because of its appealing color. Even if the color of a mineral is not eye catching, it is still more valuable than a drab, dull specimen.

Transparency
This property is not applicable to opaque minerals. For most minerals, transparency creates a different view of the mineral. The greater the transparency, the more appealing it becomes, and thus, the greater its value.

Formation of Crystals
Almost all natural crystals are deformed, some more than others. The larger a crystal, the more it is likely to be deformed. Well formed or unique crystals will raise the value of the specimen, especially of large crystals.

Size
The size of a specimen is also very important. It is easy to buy to beautiful, well formed, not-so-common minerals without a high price tag, if they are small. Larger ones with similar properties will be quite pricey. Fairly large specimens, even of common minerals, will usually have a higher value.

Luster
Luster is rarely a factor in mineral value, since the same type of minerals exhibit similar luster among each other. There are a few cases where a specimen naturally exhibits a more powerful luster than other minerals of its kind. These exceptions give the specimen a greater value.

Anomalies
Specimens of a mineral that exhibit unique, abnormal properties or are intrinsically different than normal specimens of the mineral fall under this category. Properties such as abnormal color, pseudomorphs, twinning, and odd crystals give a specimen extra value.

Presence of a Matrix
Crystals in a matrix are definitely more valuable than similar "freestanding" crystals. A matrix shows the original uniqueness of the mineral. Crystals in a matrix should always be selected over freestanding crystals.

Demand
Some minerals are valuable for the useful elements they contain. For example, many minerals composed of gold and silver may look ugly, but demand a high price because of their content.

Rarity
Obviously, rare minerals are more costly than more common ones. Extremely rare minerals have a great value, even if they look ugly. The opposite is also true. Fairly common minerals, even if nicely colored and well formed have little value because of their commonness (unless they are exceptional).

Some of the above properties can be artificially produced. Specimens can be:

• Dyed or heated to intensify color
• Roasted and oiled to eliminate flaws and increase transparency
• Cut to imitate well shaped crystals
• Glossed with substances to enhance luster
• Glued to a matrix
• Wrongly labeled to fool collectors
• Glued together from a broken fragment

One should always look for these things when purchasing a specimen.

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