Manufacturing Different Types of Gemstones

Purple spodumene also known as Kunzite
Purple spodumene also nown as Kunzite
Aquamarine crystal. Rough. Before cutting.
Aquamarine crystal. Rough. Before cutting.

I’m going to try to give people an overview of the process without getting into the fine technical aspects of gem cutting.  If I get requests from people who have technical questions I will do my best to answer them and perhaps I will expand more as time goes on.  Each type of gemstone has different properties that require a specific way of handling.  They might require lukewarm water when cutting and polishing, or they will crack.  Too much heat from friction combined with cold water when polishing can cause cracking.  Different types of gemstones need different polishing methods, and so on.  Sapphire and ruby need to be polished with diamond paste or spray.

For now I would like to discuss the two main philosophies connected with the faceting of gems.  The radiant cut and what I call the heavy bottom cut.  The radiant cuts are computer aided designs that started to be published in the 1980’s.  The diagrams have very accurate directions for the cutter.  I have hundreds of diagrams to select from that will guide me for any size or shape of rough gemstone.  I have an example to the right side of this page.  The name of the cut is Eagle Eye.  It was published by a man named Fred Van Zant.  Fred was a prolific designer of

cutting diagram
cutting diagram

gem designs and a brilliant man.  This type of cutting creates a stone with lots of sparkle from inside the stone, but also squanders a lot of good rough.  On average a 25 to 30 % yield.  That means we loose 75% of the stone!  It may also lighten the depth of color.  Something you don’t want on a good emerald; for example.  Yes, it’s great on certain types of gems that are found in large pieces.  However, it doesn’t pay to squander rough on scarce gems of high quality.  This is why hobbyists vs. cutting houses can conflict on methods.  The more or less rounded bottom (although still faceted) on commercially cut stones keeps more weight on the stone and produces a pool of color saturation that is desirable on rare stones.

From the mines to the cutting houses is also a fascinating subject.  Can you imagine buying a 55 gallon drum filled with sapphires?  What would you do with all of those gems?  You better be able to cut them. AND you better have a market to sell them once they are cut.  Everything in the barrel is called mine run.  You take those stones to your cutting house and the first thing you do is sort them by quality.  This is known as high grading.  Faceting material.  Cabochon material.  And lastly tumbling material.  And then we can break this down to other categories such as beads and melee (the little stones that surround the major stone in a setting).  Well guys; you see that it takes a factory to do this.  You invested say 1.5 million and now you need to feed your family!

So ok, I had a teacher that was a proponent of the radiant cut.  Nice work, but not that practical in the market place.  I want you to try to understand why certain collectible stones are cut the way you see them and not let yourself be swayed by the arguments of certain purists.


4 thoughts on “Manufacturing Different Types of Gemstones”

  1. This was a really fascinating topic and I was really interested in gemstones.I myself wear a ruby ring since it is supposed to bring good luck, according to my folks.
    I never had the idea of what goes on behind the scenes and one thing I’m sure about is that there is a lot of detailing and precision involved while manufacturing the right gem.

    1. I have a friend in the US named Shri. So I’m going guess that Shrey is Indian. Diamonds were discovered in India 900 years before Christ was born. This is an old, old business. I like what your family says about your ruby. That’s the magic of stones. I have seen photos of Indian brides wearing lots of gold jewelry and gemstones. It’s absolutely beautiful and not to be misunderstood as people showing off, or people who only care about money. Here we are almost 3,000 years later and we still love those little sparklers! I think that women have a special gene just for jewelry (lol). Behind the scenes there are men and women who work diligently to cut and polish gemstones. Without them and the miners who toil in the dirt all day long we could not adorn ourselves with this beauty. Thank you so much for your reply. I appreciate it. If we ever meet in Las Vegas we will go for a good curry. I’ll buy. Bob

  2. I’ve always enjoyed fossicking and have always been intrigued by gemstones as well as gold. As yet I’ve only done the “finding” part of the process, but would like to try my hand at cutting and polishing gems.

    You offer some great insight into the process, and as all gems are a little different, I realise there will be a lot to learn and I can learn it from your site.

    1. Thank you Darren. I appreciate your comment. I have been without an internet connection for 48 hours and I am behind on my correspondence. Please contact me at any time you have questions. I will be glad to help you. I studied with a man that was very knowledgeable for 3 and a half years and he taught me the basics of faceting and how to be better than most commercial faceting companies. We will talk. I am now back on line.

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