Professional Jeweler Archive: Like a Tree

June 2000

Gemstones & Pearls/Gemology


Like a Tree

Ferns, branches and fires are all represented in this fourth installment of our series on inclusions


When moisture and iron mix, the result is oxidation, better known as rust. It happens on old fences, on old water pipes and even in gemstones, when traces of moisture and iron or manganese trapped inside quartz produce oxide stains. The stains are found in microscopic fissures that cause them to branch out like tree limbs or plumes of fire. Each one is random, making the gem one-of-a-kind.

If the iron oxide stain is in clear quartz or chalcedony (a cryptocrystalline form of quartz), it’s called a dendritic inclusion (dendritic means tree-like or branch-like). It also can take on a plume-like or fire-like appearance.

Quartz can have inclusions of other minerals also, including copper-rich chrysocolla, malachite, azurite, chlorite or goethite. These inclusions have the capacity to tint their host red, orange, yellow, green, blue and black. Dendrites can occur in other gems as well, including opal and beryl.

Dendrites in quartz are an interesting and inexpensive way to introduce customers to the fascinating world of inclusions. It’s up to you to find the right dendritic quartz to tickle your customer’s imagination.

– by Robert Weldon, G.G.

The macro view of iron (yellow) and manganese (black) stains in quartz at left suggests a snow-covered landscape against a warm sunset.

Photos by Robert Weldon

At about 30X, iron oxide stains in the same quartz look like fiery plumes.

Copyright © 2001 by Bond Communications