CHARACTERISTIC
INCLUSIONS BY
COUNTRY OF ORIGIN

A gemstone expert can sometimes tell an emerald’s country of origin just by looking at it. If characteristics such as hue did not differ by source, origin would be no more than a subject of research for academia. However, because differences by source are so apparent, especially in gem-quality stones, origin has a large effect on value and, in turn, price. In many cases, characteristic inclusions can assist in determining origin, with these possibly being the only confirmation that the stone is natural. Let’s take a look at some photographs of inclusions characteristic of the primary countries of origin.

Colombia

A characteristic inclusion of Colombian emerald is the three-phase inclusion. As seen in the photograph, an inclusion consisting of a liquid phase, a gaseous phase, and a solid phase is contained within the stone. Not all Colombian emeralds will contain such three-phase inclusions, but the presence of these characteristic three-phase inclusions strongly suggests that the stone is from Colombia and that it is natural. Stones of extremely high quality once thought to be from the “Old Mine” in India are believed- from the presence of such three-phase inclusions –to actually be emeralds that had been brought to India from Spain after the 16th century.

Zambia

Emeralds from sources other than Colombia may contain inclusions of biotite mica. The presence of biotite does not prove Zambian origin, but this is the type of inclusion most often seen in material from that country. Depending on the exact deposit, many different types of inclusions may be seen.

Zimbabwe

The most characteristic inclusions in material from Zimbabwe are the fibrous crystals of tremolite seen in the photograph. Needle-like in appearance, they cross each other and are occasionally curved. These are the result of the emerald engulfing its environment during the crystallization process. Strictly speaking, the reason why natural gemstones differ from one another is that they were influenced by their environment during formation millions of years ago. This is truly miraculous, and it may even be preferable for a gem to contain inclusions to a degree that does not adversely affect its beauty.

JUDGING QUALITY

Sandawana emeralds are characteristically small, with a beautiful yellowish green color. In qualities other than accessory, they are usually not treated by fracture filling. Quality terms of K, L, and M were once used in the wholesaling of Sandawana emeralds, and the idea for the beauty grades used in this book was inspired in part by these items. K is equal to the S and A beauty grades used in this book, with L equal to B, and M equivalent to the C and D grades. There were separated into dark, medium, and light material and sold in parcels containing several hundred to several thousand pieces.

Most Sandawana emeralds are fashioned into round and square cuts with dimensions of less than 3 millimeters. A few baguette cuts and marquise cuts do exist, but because it is impossible to secure these items in consistent sizes and shapes, they are used mostly as components in one-of-a-kind, handmade jewelry.

There is somewhat of a difference in price between rounds and squares, as well as baguettes; stones that have been recut to standard sizes for use in jewelry carry a large premium.