COLOMBIAN EMERALD ROUND CUT
11mm Diameter
5.51 carat

Many gemstones, including beryls, can be heat-treated, which vaporizes and obliterates impurities. These treatments, common in sapphire, ruby and diamond, involve permanent changes to a stone's natural structure.  However, heat fails to improve the color of emerald, and there is no enhancement to similarly 'remove' inclusions from emeralds.

Emerald enhancements improve clarity by allowing liquids to enter into surface-reaching fissures, diminishing their appearance to the naked eye.  Immersion of emeralds in oil to augment their appearance is a technique dating back millennia...even before the time of Cleopatra.

It is estimated over 98% of emeralds have been enhanced. The Gemological Institute of America stated the ideal emerald filler should "hide fissures, flow into fractures, hold up over time and be removable" (JCK Magazine - June 2007).  Historically, colorless oils from Balsam or Cedarwood trees (with refractive indices close to that of natural emerald) were preferred for this use.  In Colombia, the practice of "oiling" is so common that some miners immediately deposit their crystals into an oil bucket upon harvest!

A "native cut" means that a gem has been faceted in its country of origin.  The most affordable option for faceting is usually to send crystals to factories in Asian countries, such as Thailand or China.  As a Gemstone Mining corporate report once noted, "Chinese cutting…will cut down a tree and give you a perfect toothpick, whereas Colombia would give you a log."

This Colombian Emerald from Muzo exemplifies that sentiment, as it is exceptionally large for a native-cut round.  Although there are visible inclusions, the gem was originally advertised as "no oil", so the stone presents a unique opportunity to recut a smaller, near-perfect unenhanced jewel, OR to send the piece away for Clarity Enhancement.