Gem Cutting Process

This page shows what is involved in the gem cutting process - the details of cutting one gemstone, start-to-finish. It is a process which can take hours - sometimes even days - for one stone, depending on hardness, fragility, grain, etc. This is the time, effort, and painstaking attention to getting the best out of the stone that you are paying for when you purchase a precision hand-cut, custom gemstone from Carats by Kate.

EQUIPMENT: This is the machine used for our gemstone cutting (faceting). It is an UltraTec V2D, a state-of-the-art precision machine with digital angle indicator. Mutliple diamond-coated plates (disks) are required to cut and polish stones. Besides this cutting equipment, we also have a full gemological laboratory onsite.
DIAGRAM: The design of what cut to apply to our stone has been chosen. This cutting diagram looks like this one - this is the pattern for a standard round brilliant cut. It tells what type of material can be used for this cut, what angle to use for each facet, where to place them, and every other detail needed to complete this specific design. The cut I chose for the stone below is called "Chicago Cut" - it is a slightly modified round brilliant design.
ROUGH SELECTION & DOPPING: A piece of "rough" (rock) has been selected - an oddly-shaped piece of Blue Zircon. A flat side is ground and this flat side is attached with epoxy to the flat end of a metal "dopstick". This stick locks into the cutting machine and controls handling and placement of the stone during cutting.
ROTATION: With the dopstick locked into the machine, cutting angle can be controlled to the 100th of a degree and the stone rotates cut multiple facets. With this piece rotated 90 degrees, you can see the other side...very roughly shaped. Can you imagine it yet as a sparkling finished gem? A good cutter can already see that - and bring out the natural beauty locked inside the stone.
ROUGHING IN: The horizontal plate is the cutting surface. It is spinning - speed and direction are controlled at the bottom right. First, a very rough (100 grit) plate is used, switching to finer plates as the process continues. The digital readout shows the angle currently positioned to cut. The mast is lowered until the rock makes contact with the spinning disk and it is cut away until the proper angle is reached.
PREFORM STARTED: The first set of facets are cut in roughly, using the most coarse disk. This is the beginning of a "preform" shape. What you are looking at will be the bottom, or pavilion, of the gemstone. The point is the culet - the tip of the bottom of the stone.
PREFORM DONE: An approximate "girdle" is cut to match up with the pavilion facets. By roughing this in, the finished size of the gemstone is determined. Because this stone was oddly shaped, the irregular parts had to be trimmed away to leave a perfect circle. The maximum size obtainable from this irregular stone will be a 7mm (millimeter) finished stone.
FINE CUTTING: Switched the diamond-coated plate to a medium-fine disk, and all facets are ground again. This removes the top-most rough layer; you begin to see some shine and a brighter color. Major scratches are removed and the clarity of the inside of the stone is more visible.
PRE-POLISH: Switched diamond-coated cutting plates again to to a very fine disk. All fine scratches and pits are ground away so that only a smooth surface remains. Final dimensions are pretty accurate at this point.
POLISH: By changing to a different type of plate, we now switch from cutting to polishing. The facets take on a glassy sheen as they are perfectly polished. Some cutters polish the girdle; some leave it unpolished. An unpolished surface looks smooth, but fuzzy, like a piece of etched glass.
BEGINNING NEXT FACET: Now that the main facets have been cut, the next set of "stars" go on, starting at the culet (center point) and reaching down to the girdle. This first new facet is only half-way completed - it still has to be cut to reach the girdle.
PAVILION DONE: Star facets go pretty quickly - less surface area to cut and polish than before. In this photo, all facets are done and the pavilion is finished. And, if you can tell from this shot, we polsih our girdles. The stone should be transparent to semi-transparent now (you are able to see through it).
TRANSFER: The stone is removed from the cutting machine at this point. The dopstick on the right is what you have been looking at. The dopstick on the left is new...jeweler's wax is melted into a cone-shaped end and it seals to the finished pavilion. This contraption allows a perfect transfer of stone so cutting can continue. When cooled and set, the right dopstick is removed.
CROWN FACETS STARTED: The dopstick goes back into the cutting machine and is aligned to match where the girdle facets rest. When perfectly aligned, a ring of cown (top of stone) facets is cut. This also creates a thin girdle, usually about 3mm thick. This top point will soon be cut away to make a flat top, or table, on the stone.
CROWN DONE: After main facets are cut, any secondary facets are applied in the same way. Finally, a special adapter is needed, the stone is re-aligned again, and the flat table is cut. Perfect table and crown facets are vital - that is how light enters the stone. The perfect pavilion facet angles help disperse the light and that's how you get sparkle!
TABLE CUTTING: This also shows the table being cut. The tiny circle starts in the cneter and spreads. The object it to make it reach the corners of the appropriate other facets, filling the space in between.
FINISHED STONE: When done, the jeweler's wax is heated and the stone is removed from the dopstick. Any residual wax is cleaned away by hand. The stone is thoroughly washed and inspected under 10-15x magnification. Stone is weighed and recorded. Any internal inclusions are documented.

	THIS IS THE LISTING FROM THE "Gemstones - New" PAGE: Zircon (blue) (this stone has a natural internal crack close to the girdle edge - barely visible and not reaching the surface) Source: Cambodia Size: 7mm round Weight: 1.97 cts Cut: Chicago Cut pattern