Calibrated Gemstones

Most of the time, when we’re working with materials worthy of custom-cutting, we aren’t going to be producing calibrated gemstones – chopping the rough down to a specified size – because we’re working to preserve every tiny bit of the gem.

In those instances where we’re tasked by a jeweler with producing a stone to fit an existing setting – or if we’re producing a stone to fit a standard commercial setting – it’s important to have the skill of calibrating.

Although we cover calibrated gemstones (and how to calibrate them) in the live academy, faceting designs that show a step titled “calibrate length” or “calibrate width” can still be puzzling for some students.

All this means is if you intend to calibrate the stone (make it a specific size), the step with that instruction is the step where that is to be done.

For instance, in my 85-facet design “Easy Omni Oval”, the first step of cutting the pavilion is to cut 16 facets, on various indexes, to a point at 44 degrees. When that step is complete the gem will look like this (GemCAD):

calibrated faceted gemstones

The very next step says “calibrate length”. It is a set of girdle facets cut on the 21 index, which leaves the gem looking like this (GemCAD).

calibrated faceted gemstones

So, we’ve cut the END facets of the oval pattern, dictating the LENGTH of the finished oval. If we want that oval to be a specific size, we can calibrate (measure) the length – adjusting mast height and trimming more as necessary – to produce the exact length dimension desired.

My “Easy Omni Oval” faceting design has a L/W ratio of 1.237. So, if we calibrate the length to 10mm, the width should complete at about 8.08mm – which is well within the tolerances for a commercial 10x8mm oval setting.

calibrated faceted gemsSo, wherever a design gives the “calibrate length (or width)” step, you can usually change that dimension at that step without affecting the remainder of the design. It’s your opportunity to adjust in that way, because afterward changing the dimension will no longer be trivial. This should make it easier to cut calibrated gemstones whenever the job requires it. Happy faceting!

Posted in Apprentice Blog, Beginner Stuff | 1 Comment

To cut or not…

I get this question frequently:

>>Did you cut the bowl on your machine so that you can make your 90’s on the girdle?

The answer is NO: I DO NOT RECOMMEND chopping-up a perfectly good splash bowl. And, I have never had a problem cutting a girdle. I don’t recommend faceting machine modification. I recommend skill-building – and in some cases, making an accessory.

I fold, or curl – the edge of the bowl inward with one finger. I usually use the middle finger of my left hand – which leaves the index finger free to help manage the stone. I can prevent the gem from slipping off the edge of the lap, or apply a little downward pressure. I’m a two-handed faceter, so I manage the quill with my right hand.

A person can also make a hook out of a coat-hanger wire. Mine is about 2 inches wide across the top (part that catches the bowl).

splash bowl accessory for faceting machine

Then, it comes together into a single hooking base that can be inserted into the hole in the machine base. If you make it the right size, you can curl and compress the bowl and the hook will go into the base, holding the rim of the bowl down securely.
faceting machine accessoryBesides, the bowl edge makes a nice place to rest the dop while you’re checking a diagram or doing other stuff between facets…

Posted in Beginner Stuff | Comments Off on To cut or not…

Getting Started in Faceting

Whenever it’s “Academy Time” I get lots of questions about what a person needs to get started in faceting:

“What’s in the “beginner’s kit?” people will ask?

And, there aren’t many one-stop shops for all this stuff, though there are plenty of guys who will try to sell you their kitchen sink and the old AMC Pacer sitting on blocks in their side yard, too. The real list isn’t that long – or that expensive, alongside the price of a shiny faceting machine.

To help my Academy students, I compiled a checklist document with both required and recommended items – and also a video to help with familiarity.

So, if you’re excited about getting started in faceting, and you want an honest list of the stuff you really need, check those links and feel free to save the checklist document and use the embedded links to get to your items quickly.

Posted in Beginner Stuff | Comments Off on Getting Started in Faceting

Remember the SMALL DOPS

For Faceting Academy attendees (and other apprentices), remember that YOU WILL NEED SMALL DOPS.

We (you) are going to be cutting some VERY small stones as part of your training. This is the fastest way to learn all of the relevant skills, from evaluation to orientation, dopping, transfer, cutting, polishing – and most importantly SEEING – training the eye to see those tiny facets, meets, and polish issues.

This will also allow you to complete the entire cutting process REPEATEDLY – RAPIDLY – and that’s key to fast learning.

So, be certain to acquire AT LEAST 3 sets (flat and cone) dops at the 2 or 3 mm size.

I *recommend* that you get two at the 2mm and two at the 3mm size (per person).

Posted in Apprentice Blog | Comments Off on Remember the SMALL DOPS

Which Faceting Machine is Best?

I get this question at least a couple of times a week – people want to get started in faceting and they want to get the “best” machine…

If I were a new driver, and I came to you and asked “what is the BEST automobile?” – what would your answer be?

If there really were one “best” then wouldn’t everyone buy the “best” one, and the non-bests would go out of business?

Continue reading

Posted in Beginner Stuff | 2 Comments

4.05 carat Emerald from the MOM



Video of a 4.05 carat Emerald cut on the new MOM (multi-optic machine)


Posted in Beginner Stuff | Comments Off on 4.05 carat Emerald from the MOM

The Faceting Academy New Launch

July 22nd, and the NEW and upgraded Faceting Academy site is about to launch. From the foundation of a new platform on a really great hosting company with really great support team, I’m ready to promote the next level in promoting the art and science of faceting in America.

I’m looking forward to a great Fall season of new things – from the resident Faceting Academy 2011, to the inauguration of our new MOM (multi-optic machine) for unleashing wild new creative opportunities for the faceting community.

Tune in, turn on, and enjoy!

Posted in Beginner Stuff | 1 Comment

Welcome to the Academy Blog!

Here you’ll find the latest

  • gem and faceting stories
  • photos of the latest gems
  • information about faceting-related shows, classes and events
  • new faceting tools and techniques
  • new faceting designs
  • and more!

Browse the information, and feel free to contribute to the discussion. ASK ME a question, or suggest a topic!

Posted in Uncategorized | 4 Comments