April 9, 1901 – No need to grind away the top of the Octahedron
William “Bill” D. Hoefer, Jr. GG (GIA), FGA is an educator, and an expert in appraisal law. On a typical day, you can find him on his website, Appraising Demystified. Over the past few years, in his patent research to locate gemstone diagrams for his Perfect Diagram software, Hoefer has come across some very interesting patents that he is sharing with all of us here in the Roskin Gem News Report.
Case in point, and the first one we’re going with, is a patent from April 9th, 1901. A Mr. E. Loesser filed for a patent titled “The Art of Working Diamonds,” describing a method that used diamond-encrusted saw blades to cut through an octahedral diamond crystal—creating two facetable stones instead of grinding away the top of the crystal and ending up with only one cuttable diamond.
Could this have been the first time someone figured out a way to actually saw a diamond in two? Let’s check out his patent!
When Diamonds Were Turned to Dust
A 1901 Idea That Changed How Cutters Looked at Rough
Before 1901, there was really only one way to cut a diamond into two pieces: cleaving. You found the octahedral grain, set a thin steel wedge against the crystal, and struck it with a mallet in the direction of the grain. When everything went right, the stone split cleanly. The break was smooth and flat, in the octahedral direction – the “cleavage plane.” When it didn’t go right, you could damage the crystal. Cleaving was considered both a skill and a gamble.
If a diamond needed to be cleaved, then once the cleaving was performed, the rest of the job was about grinding. For the most part, whatever stood in the way of the diamond’s final shape, that part of the rough crystal was simply ground away—first with heavy, coarse grit to remove more diamond quickly, and then with finer and finer grit to give the surface its sought-after adamantine luster.
Ernest Loesser looked at that process and thought, there has to be another way. We are losing too much diamond by grinding it all to dust!
It’s a Grind
What bothered him most wasn’t cleaving — it was what came after. For a typical octahedral crystal, the entire top pyramid often had to be ground away just to create a flat table.
Sidebar: As you probably know, the “table” is the large top facet on the finished diamond. If we are grinding away at the diamond crystal to create a table facet, then we stop grinding as soon as possible. Hence, small tables were the rule, not because of the appearance, but because of lesser weight loss!
Grinding away the top of the crystal wasn’t a tiny sacrifice; it was a meaningful piece of diamond disappearing into powder. Loesser’s question then was simple – and unheard of for the time: why not cut that part off cleanly instead of grinding it into dust?
So in 1901, he proposed something diamond cutters hadn’t seriously considered before — sawing a diamond straight through. Not along the octahedral grain, but along a plane perpendicular to the north/south axis of the octahedron.
Inventing the Diamond Saw
Loesser’s patent describes a razor-thin, fast-spinning metal disk, embedded with diamond grit, that starts the sawing at “a corner of the crystal” and moves through the stone at an angle to the octahedral grain. Against all conventional wisdom, it worked. The diamond didn’t shatter. The removed portion stayed intact. So instead of losing that top pyramid forever, cutters could now save it and turn it into another faceted stone.
The Added Bonus – Polishing
And here’s the part Lesser may not have set out to invent, but noticed and documented anyway. As the blade cut through the diamond, it created diamond dust — unavoidable, of course. But some of that dust didn’t fly off into the air. It clung to the face of the spinning blade and was dragged back across the newly exposed sawn surfaces. Diamond polishing diamond. The two fresh faces — which would later become the tables of both stones — came off the saw already partially smoothed.
Suddenly, one piece of rough that once yielded a single round brilliant and a pile of dust could produce two cuttable diamonds, with less grinding required afterward.
If you were to tell someone about that technique today, the idea would seem obvious. But in 1901, it was anything but. Loesser didn’t just introduce a new tool — he quietly changed how cutters thought about rough, about yield … and about how much loss everyone had simply accepted—until Loesser came along and asked “Why?”
We’ll be back again soon with another patent, courtesy of Bill Hoefer, Jr. GG (GIA), FGA
