Rock of the Month
April 2013
BY Jan McClintock
TOPS A Rock Shop
San Juan Bautista
The Rock of the Month for April is Druzy or Druse. OK, it’s not exactly a rock but rather a form of crystal – but it is beautiful and very popular in jewelry. Druzy is a fine coating of crystals on the surface of a rock, in a crack in a rock, or inside a vug (hole in the side of a rock) or geode (a hollow inside a rock). The crystals often glisten in the light creating a sparkling display of color.
The most common druzy crystals are quartz. Quartz druzy is commonly found on chert (think jasper) or agates. Druzy is found all over the world including San Benito County. The most common San Benito County druzy is quartz, calcite and black andradite garnet.
The “hardness” of druzy depends on what makes the druzy. Garnet and Quartz druzy is fairly hard and therefore durable because quartz and garnet are hard minerals (6 – 7 on the MOHs scale of hardness). Other druzies such as calcite or dolomite are softer (3 – 4 on the MOHs scale of hardness).
For jewelry, quartz and garnet are generally the druzies of choice. Quartz druzy can be treated with a metal vapor coating of gold, titanium or platinum to create spectacular color effects. Uvarovite garnet is a natural bright green and can be used in jewelry without treatment.
Whether you are looking for a great specimen or a unique piece of jewelry, druzy is one of Mother Nature’s bountiful delights. Stop by the store and check out our druzy collection!