What makes a gemstone sparkle?

Now that you’ve completed your prerequisite Lapidary One course, it’s time to move up the gem ladder to faceting! So, what’s a facet? A facet relates to the word face, which is one of the flat polished “faces” of a faceted gemstone like a genuine diamond, emerald, ruby, sapphire, amethyst, topaz or other less expensive gems like a man-made zircon. Can you tell the difference between a real diamond and a zircon? (Most people cannot!)

In Lapidary One you learned how to take a “rough” rock and cut a flat bottom with a rounded top (cabochon), and now it’s time to learn how to cut facets onto a faceted gemstone. Did you know it’s just as easy to cut and polish facets as it is to make a cabochon? So, what’s the difference? The difference is the sparkle. Also note that gemstones which sparkle are highly prized and usually more valuable than a cabochon. Cabochons are shaped and polished smooth, but with a faceted gemstone, you actually cut each and every face on the stone. One of the most common cuts is the round brilliant cut with 57 or 58 facets! These polished facets give the final gem its extraordinary beauty and high flashes of brilliance – hence, the sparkle.

Okay, so how do I sign up? Just show up at the Sun Lakes Rock, Gem & Silver Club meeting at 10:00 a.m. on Monday, December 17, at the Sun Lakes Country Club Navajo Room. It’s easy, and the best part is you’ll be making new friends from over 200 members in our club.

There are four simple elements to cutting facets…

1) A piece of natural or man-made crystal to cut (Your instructor will help you obtain.)

2) A faceting machine (The club’s Phase One shop has the machine.)

3) Abrasive disks to do the cutting and polishing (ditto above)

4) A person to set and hold the machine (The club provides the instructor, and you are the student!)

Faceting methodology consists of mounting a gem crystal on a metal dowel (dop stick), which fits into a quill, then rigidly addressing the H.A.I. (Height, Angle, Index) triangle with the faceting machine and touching the locked-in-place crystal to abrasive laps in two sequential operations, faceting first the bottom (called the “pavilion”) and then the top (called the “crown”).

Height: controls the depth to which the facet is cut, and this enables a faceter to establish even, uniform rows of same-sized, same-depth facets. Angle: establishes the plane upon which each facet is cut, because optics and performance is so dependent on each facet(s) possessing just the right amount of plane or slant.

Index: refers to the placement of the facets around the shape or outline, i.e., a round brilliant cut stone, like most diamonds, shows eight main facets when viewed straight down in “plain view.”

That’s all there is to cutting your own faceted gemstones!