How to Measure a Quartz Crystal

Use a tape measure or a ruler to determine the physical dimensions of the quartz crystal. It is also important to record the shape of the crystal, as quartz crystals can be almost any shape. Most commonly, quartz crystals are pyramidal, prismatic, geoidal, sceptered, or concretionary. Measure the length of the crystal, and the width and breadth of the crystal at the widest points.

Obtain a mass measurement by using a scale or triple beam balance. Record the result to the correct number of significant figures. To measure the volume of the crystal, use the water displacement method: fill a beaker halfway and measure the water level, then place the quartz crystal in the water and measure the new water level. The amount of water displaced (in mL) is equal to the volume of the crystal (in cc).

Measure additional quantitative properties of the crystal, if desired. Testing the hardness of a mineral is based on the Moh's scale, which uses standardized levels of hardness based on existing minerals. Quartz represents a hardness of 7 on the scale, but an individual sample of quartz may have a different hardness than those of a standardized Moh's scale piece. If desired, the cloudiness of quartz can also be measured with a spectrophotometer.

Observe and record the qualitative properties of the crystal. Be sure to note the shape, color, opacity, and presence of any other minerals in the crystal.