Sometimes, a gemstone undergoes treatment to increase its beauty, durability, or value. Most gems available today have some treatment. Fissure filling is one such treatment.

Fissure filling, also known as fracture filling, is the process of filling in small fissures on the surface of a gemstone. Fissures are small, narrow gaps on the surface of the gem. The treatment improves the clarity of the stone by concealing these tiny cavities.

We use several types of materials when fracture filling a gem. The most common materials include glass, resin, and oil. For the most part, these fillers are colorless. This is so the color of the gem is not affected. If using a dye to improve the gem’s color, it should be described as fissure filled and dyed.

Niassa Ruby and Diamond Accent Ring in Platinum Over Sterling Silver

Niassa Ruby is an example of fracture filling a gemstone.

Does fissure filling affect the value of a gem?

Yes. Any stone that occurs naturally and does not require treatment will command a higher price than a treated gemstone.

Treating stones provides the opportunity for owning gems that many might otherwise feel priced out of ever owning.

What stones are fissure filled?

At Shop LC, the two most common fissure filled stones are emerald and ruby.

Many, if not most, emeralds are fracture-filled with colorless oils. The most commonly used oils include palm, cedar, and balsam.

For fissure filled rubies, the most common material is special glass with high lead content.

Kagem Zambian Emerald and Natural Champagne & White Diamond Ring

Oiling, a type of fissure filling, is very common with emeralds.

How do I care for fissure filled gems?

As with most gems, the best way to care for them at home is by scrubbing them with a soft-bristle toothbrush and warm water and dishwashing liquid solution.

Avoid placing these treated gemstones in an ultrasonic or steam cleaner, as these can damage the stone. Also, some chemicals or high heat can cause the treatment to warp or alter.

Some fracture filling materials, like oil, may need replacement. Oiling emeralds is a widespread treatment, and many jewelers can do this for you.

For more information on gems, be sure to visit the Education Center.