Rectangular Portuguese-Style Cushion Cut

First I started with a square version I did last year. You can find this one on facetdiagrams.org.

To turn our square cushion into a rectangular cushion, we will in effect saw the stone in two along the two red lines, throw away the part in between and glue the two halves back together. To do this in GemCad, first download the file from facetdiagrams.org, open it in GemCad. After you open the file, move your cursor to the point highlighted in yellow above. Left click. Click Use to Cut. Then recenter the stone about this point. Do Edit->Center menu command, and do the following:

1. Check the Y checkbox
2. Check the Use point 1... radio button
3. Click OK

GemCad will offset the stone. Then reflect the bottom half. Do Edit->Reflect, check the Y checkbox and press OK. You should get something that looks like this:

Then you can recenter and re-scale. Do Edit->Center with the default choices and press OK. This will in effect lengthen the dopstick, sliding the stone along its axis until the stone's center of mass is at the center of the side view. Then do Edit->Scale, check the All box and press the Automatic button. Hint: It's a good idea to do these two steps to any design before you save it. This will center it pleasingly and make it as large as will easily fit on the screen.

Then you should get something that looks like this:

OK. This was pretty straightforward. However, the table is too skinny, to my eye, at least. The easiest way to fix this is to cut the table deeper, cutting off step G in the process. Move your mouse pointer to the meetpoint highlighted. Left click and click the Use to Cut button. In the New Facet Info box, enter an angle of 0 and click the Apply/Cut button. GemCad will warn you about cutting off facets. Answer No to the question about saving them to preform.

I don't really like the keel on the bottom, so let's get rid of facet 10. Put your cursor inside facet 10 so that whole facet is highlighted. Left click and click the Delete Tier button. Also, you might notice that our new lowest angle facet, labeled 9 is at 45°. We really want this to be around 42° (quartz or beryl) or 41° (everything higher in R.I.). Click in the facet labeled 9 and type 42 (or whatever culet angle you want) in the new angle box and click the Apply button.

OK, we have all of the facets. Let's work some on the cutting order. Do Edit->Sort and select Girdle-Pavilion-Crown for the order. Then do Edit->Rename in order and select the default choice. The result is the following.

I have to admit that I left out some steps. I went back and edited the angles to round them to the nearest half of a degree. To do this, I clicked on a meetpoint I wanted to preserve for a facet, clicked inside the facet, made a mental note of its rounded angle, clicked Uncut/Recut. Then I typed the rounded angle in the Angle box and clicked Apply/Cut to re-cut at the new angle. (The Uncut/Recut process preserves the index number). I did this for all of the pavilion facets.

I posted this design on facetdiagrams.org. I called it "Cushport." It is design number 08.146. You can download it there.

In my next blog post, I'll talk about the cutting sequence for this design.