ALEXANDRITE BUYING GUIDE
Alexandrite is the most sought after gemstone for its kind. It’s extreme rarity and characteristic of color change makes it the most desired stone since 1830. The stone exhibits Green in sunlight and Reddish in incident light where the source of light is yellow to reddish.
Alexandrite’s color changing phenomena makes it very rare and even the artificial stones are expensive. The price for alexandrite is decided based on a number of factors yet the intensity of color change makes a huge difference in the prices.
Alexandrite should exhibit emerald green to peacock blue in the sunlight and reddish of ruby under incident light or amethyst hue. The color change of these stones are described as a percentage for instance if the entire stone changes its color under different lighting conditions it is considered 100% color change which is hardly unusual to come by. Highest quality alexandrite will exhibit a change percentage of 83% to 94% in meaning some facets or parts in the stone will not respond with a colour change.
A quality alexandrite will display 74% to 85% colour change when the stone has a darker tone which is more responsive to the colour. In most cases alexandrite will show 45% to 65% color change. However a buyer should be extremely careful about the light source. A light with 5000 to 6500 kelvin temperature will emulate day light and 3000 to 3300 kelvin temperature will resemble reddish incident light. Intensity of the light will have an effect on the color change where the buyer should exercise diligence. Therefore, the value for alexandrite is primarily decided by the intensity of color change.
Alexandrite does not come clean most of the time. The color changes are intense in the stones with inclusion and impurities. A Buyer needs to reconcile with the clarity and colour change before buying a stone.
Since typically Alexandrite occurs with inclusions and their rarity makes the seller focus more on retaining the weight. Most Alexandrite are not well cut but the cushion cut, oval cut, round cut are common.
Alexandrite above 1 carats are rare enabling them to command a higher price with increased weightage. Stones generally with higher carats exhibit lesser color change and clarity. Therefore, making an exceptional size above 8 carats is extremely valued.