Good VS Bad Gemstone Cutting. How to tell the difference!

In thin tutorial we are going to discuss how to detect the difference between a well cut and a poorly cut gemstone We'll explain how to recognize a windowed gem Facets that don't meet poor polish and crooked girdles This will help you distinguish between well cut gems and poorly cut ones One of the most common signs of poor cutting is the window in many cases such as this. you can actually read through the gem. So, what makes a gem have a window? A gem is windowed because it is cut at the wrong angles This is usually due to either primitive equipment or an attempt to get as large of a gem as possible out of the rough. with a disregard to optics and proper cutting angles In this illustration the orange line shows the path the light follows through the gem You can see that in this gem which is cut with angles that are too shallow the light goes directly without coming back. This creates a window and reduces the total brilliance of the gem. In contrast, this gem is cut at the proper angles and the light which enters the gem is returned back in brilliance and beauty to the viewer. Another way to recognize a window is when you see a ring of brilliance around the outside of the gem and the middle is dead or dull looking like the gem shown here. Here is another gem with a window or a blank middle which is also known as a fish eye. Here are two examples of gems that are well cut and no fish are involved. Fantasy cut gems have a whole set of rules of their own They sometimes will use windows as a design element. and since they're cut for artistic purposes This is acceptable and the overall affect is attractive. Meet points are best seen using partially reflected light like the whitish facet in this picture This allows you to see how the corner of the facets meet or the meet point Straight lines and good meet points are a sign of a quality of a well cut gem. Another sure sign of sloppy cutting is a poor scratchy polish like this. It's best to examine the polish with some magnification. using partially reflected light as when checking the meet points. To give a gem a high polish, takes three to ten times longer That's why lines that meet and polish, are some of the easiest way how much time and care was taken during the lapidary process. Also, Check the girdle, which is the widest part of the gem Think of it like a belt that goes around the middle of the gemstone. The girdle should be straight and of an even thickness all the way around the gem. This is important because the girdle is where the gem is gripped by the pros when they are set in jewelry If poorly cut gems like these seem familiar to you, Don't be surprised The great majority of gems in the market today are poorly cut. Most are cut overseas using antiquated equipment. Where speed is of more importance than bringing out the gem's maximum beauty. Hasty and careless cutting results in windows, crooked meet points, and scratchy polish On the other hand a well crafted gem is a thing of rare beauty. and all the extra lapidary care and skill, which is required, is well worth it. So, remember when selecting your next gemstone take an extra look at the middle of the gem The meet points the girdle and the polish.

Channel: John Dyer

Views: 165,757

Keywords: wholesale gems, color, colour, green gems, yellow gemstones, raw gems, buy gemstones, facted gems, natural gems, jewelry, julia behrends, design, artistry, creative, fantasy cuts, dreamscape, unique, untreated, loose gemstones, cut gems, purple gemstones, for sale, good vs bad cut, well cut gems, beautiful gems, john dyer gems, gemstone cutting, cutting gemstones, how cutting effects, good gemstone cutting, bad gemstone cutting, windowed gemstone, gem cutting, faceting gemstones

Id: eG-vX1OFWXo

Length: 5min 7sec (307 seconds)

Published: Fri Apr 20 2012