Chapter 2: Guided Tutorial — Cut Your First Round Brilliant

In this chapter, you will cut a complete Standard Round Brilliant Quartz Gemstone (RI = 1.54, 96 index gear) using only your mouse in the Interactive Slicer. Follow along step by step directly in ProFacet Studio!

Step 1: Click New to Mount a Fresh Round Preform

1. In the top toolbar of the right-hand pane, click New.
2. ProFacet creates a clean 16-sided round preform (Round(43, 16)) on a 96-tooth gear and automatically sets the 3D Viewport to Palette mode so you can see individual facets and meetpoint markers clearly.
3. Click the ⌄ (Show display options) button in the top-left of the 3D viewport and turn on Facet Info so every facet displays its Tier:Index label.
4. At the bottom-left of the 3D viewport, click Pavilion (Flip View | Crown | Profile | Pavilion) so you are looking straight at the bottom of the blank.

[!NOTE] What Is That Green CAM · Round 43° · ×16 Row? Instead of making you manually cut 16 temporary centerpoint facets and 16 vertical 90° girdle facets just to get a round cylinder, Round(43, 16) does that preform work in a single step! Notice the golden diamond (♦) in the center of the Pavilion view—that is the centerpoint (cp()) where our Pavilion Mains will meet.

Step 2: Cut the 8 Pavilion Mains (P1) Anchored at the Girdle (gp())

First, we will slice 8 kite-shaped main pavilion facets at 41.00° (safely above Quartz's 40.5° critical angle) starting from the 8 outer girdle corners (gp()) and meeting at a brand-new central culet:

1. Above the vertical masts on the right, make sure Pavilion is active.
2. In the top Precision Dial Deck, set the three horizontal drums:
   • IDX: 3 (aligns with the girdle corners of Round(43, 16) at 03-15-27-39-51-63-75-87)
   • SYM: ×8 (cuts 8 evenly spaced facets around the 96-tooth gear)
   • MIR: OFF
3. In the ANGLE box on the right mast, enter 41.00.
4. Click ↓ Jump in the action bar below the Tiers table so the cutting plane slides inward to touch the outer girdle corners (gp()), then click +Meet to lock it to gp().
   • Why anchor P1 at gp() instead of cp()? Because Round(43, 16) already cut a 43.00° preform cone to the old centerpoint (cp()), a shallower 41.00° cone passing through that same cp() would float outside the stone in thin air! Anchoring P1 at the outer girdle corners (gp()) slices deeper into the pavilion from the rim, carving 8 kite-shaped Pavilion Mains that meet at a new central culet while leaving 16 temporary PF1 triangles around the rim.
5. Click Commit ✓.

Look at the 3D viewport: your 8 kite-shaped P1 pavilion mains now meet cleanly at the center, while 16 temporary preform triangles (PF1) remain around the outer rim.

Step 3: Cut the 16 Mirrored Pavilion Breaks (P2) Meeting the Girdle (gp())

Next, we cut 16 steeper Pavilion Break facets (P2) at 42.40° to cut away every remaining temporary PF1 preform facet and establish a level, scalloped 16-facet girdle:

1. In the Precision Dial Deck, configure a mirrored 8-fold tier centered on the P1 mains (IDX = 3):
   • IDX: 3
   • SYM: ×8
   • MIR: ±3
   • How this works: At each of the 8 main positions (03, 15, 27…), MIR ±3 cuts two break facets (3 - 3 = 0 and 3 + 3 = 6, etc.), producing all 16 break facets (96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90) aligned with the 16 girdle facets!
2. Set the vertical ANGLE mast to 42.40 (steeper than P1's 41.00°, and slightly shallower than PF1's 43.00° so it slices deeper into the stone from the girdle rim and completely replaces all 16 temporary PF1 facets).
3. Click ↓ Jump and then +Meet so P2 locks directly onto the outer girdle points (gp()).
4. Click Commit ✓.

The Pavilion is now 100% finished—every temporary PF1 preform facet has been cleanly cut away, leaving 8 P1 Pavilion Mains framed by 16 P2 Pavilion Breaks!

Step 4: Flip to the Crown & Cut the Crown Breaks (C1) and Mains (C2)

Now let's flip the stone over to cut the upper Crown dome:

1. Above the vertical sliders on the right, switch from Pavilion to Crown.
2. At the bottom-left of the 3D viewport, click Crown to look straight down at the top of the stone.
3. Cut the 16 Crown Breaks (C1):
   • Set the drums to IDX = 3, SYM = ×8, MIR = ±3 (matching the 16 Pavilion Break and Girdle facets below).
   • Set ANGLE to 42.00.
   • Click the +girdle button in the bottom action bar, then click ↓ Jump and +Meet (gp() + girdle).
   • Why +girdle? The very first Crown tier that touches the Pavilion girdle needs + girdle so ProFacet leaves a clean vertical girdle band (3% of stone width by default) between the Pavilion and Crown instead of pinching the girdle to a knife-edge.
   • Click Commit ✓.
4. Cut the 8 Crown Mains (C2):
   • Set the drums to IDX = 3, SYM = ×8, MIR = OFF (matching the 8 Pavilion Mains at 03-15-27-39-51-63-75-87).
   • Set ANGLE to 35.00.
   • Click ↓ Jump and +Meet to lock C2 to the girdle corners (gp()).
   • Click Commit ✓.

Step 5: Cut the 8 Star Facets (C3) & Polish the Table (T)

Finally, we add the 8 shallow Star facets (C3) and the flat 0.00° Table (T):

1. Cut the 8 Star Facets (C3):
   • Set IDX = 9 (halfway between the Crown Mains at 3 and 15), SYM = ×8, MIR = OFF.
   • Set ANGLE to 22.00.
   • Click ↓ Jump and +Meet so C3 meets the upper tips of the Crown Breaks (mp(C1)).
   • Click Commit ✓.
2. Cut the Flat Table (T):
   • Set IDX = 0, SYM = ×1, MIR = OFF.
   • Set ANGLE to 0.00.
   • Click ↓ Jump and +Meet so the table meets the inner star/bezel tips (mp(C2)).
   • Click Commit ✓.
3. Inspect Your Finished 73-Facet Crown in Palette Mode:
   • Keep the viewport in Palette mode with Facet Info enabled to verify that all 33 crown facets—16 C1 Crown Breaks, 8 kite-shaped C2 Crown Mains, 8 triangular C3 Stars, and the central octagonal T Table—meet at razor-sharp vertices. (Whenever you want to preview optical brilliance and spectral dispersion, you can toggle the top-right shading dropdown from Palette to Raytraced or BDPT.)

In Chapter 3: Inside the Interactive Slicer — Dials, Masts & Meetpoints, we will explore every advanced capability of the Slicer, including in-place tier editing, explicit tooth lists, and Edgepoint (Edge) mode.