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How to grade a mineral

Minerals are works of art, each mineral is totally unique and can be judged by a multitude of criteria. Some criteria are subjective (in the eye of the beholder), while others can be quite concrete. This grading system is a guide designed to help collectors assess how any given specimen ranks among its peers.

As a guide, it provides reference points while still leaving open the possibility that a specimen can be beautiful and treasured simply due to the fact that you enjoy its appearance or that it moves you.

It is here that the worlds of art and nature meet.

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How Our Grading System Works

There are two sections to the guide: Section A with five criteria, and Section B with four criteria.

Each individual criteria is graded out of ten, ten being the best possible and most desirable score. Add up all nine criteria and then divide that sum by nine. This will give you an average score.

Of course there are some specimens where specific criteria are not applicable. In those cases, add up your individual criteria scores, then divide by the number of criteria used to get to your average score.

Please note that this guide is to help collectors assess their collections. A high score does not necessarily denote a high monetary value.

Glossary

Average Scores

9-10 - Exceptional quality

8-8.9 - Very good quality

7-7.9 - Good quality

6.9 > - Not of collectible quality

Section A

Focuses on the quality of the crystal

Section B

Focuses on the quality and relationship between both the crystal and the matrix

ii. Balance

Back to Criteria
Wilensky Approach

Balance

This criterion is very related to aesthetics. How do the crystals and matrix relate to each other in size, ratio, and form? How do they interact with space? We consider angles, length, thickness and arrangement of these crystals. They should look proportional to each other, juxtaposed in an interesting and eye appealing way, or on a matrix in such a way as to be harmonious and counter-balanced.

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