Lab Emeralds are cut from hydrothermal grown emerald crystals. Hydrothermal growth takes place over an extended period of time, under pressure. These crystals are manufactured for the gem and jewelry trade and have no scientific applications. They are not repurposed gems like many of the other types in this guide.
The crystals have a maximum thickness of about 35 mm (too thick results in too many cracks), but must be split into two halves because the seed crystal (the catalyst for growth) that travels through the middle would show up in cut gems otherwise. Crystals are typically divided in A, B, and C grades as well as two types of colors; a lighter green "Colombian" color and a darker "Zambian" color. A 15mm A grade Colombian half boule is a rare crystal.
We treat all lab emeralds the same way we would treat any precious natural emerald. Once cut, we oil the emerald under extreme pressure using an Opticon polymer. Unlike cedar oil, opticon is colorless and provides a permanent seal.
Emeralds are an important gem material with a unique vivid green color.