Checkerboard

Checkerboard crowns stretch facets into squares across the table, yielding bold sparkle even on shallow stones. This layout is popular for colored gems that rely on saturation rather than brilliance.

Design Highlights

• Square outline with evenly spaced crown facets to create the grid effect.
• Flatter crown to keep the table broad while still offering relief cuts.
• Pavilion angles tuned shallow to keep depth low for weight retention.

FSL Spec

Note: the design below is adapted from the "GemCad Advanced Tutorial". This is not an easy one, but the idea is to create points in a 4x4 grid, project one after another on the facet above and cut a new tier. The angles are optimized for quartz. There is an easier 3x3 checkboard in the Fred and prz Example

set name "GemCad Advanced Tutorial"
set ri 1.54
set gear 64

G1 3 @ 90.00 : 0.9500 xx 4
C1 1 @ [54.983] : cp

let midp1 = ep(edge(C1:1, G1:61), 0.5)
let midp2 = ep(edge(C1:31, G1:35), 0.5)
G2 1 @ 90.00 : midp1

let pu1 = fred(midp1, midp2, edge(C1:1, C1:15))
C2 3 : midp1 : pu1

let fr2 = fred(gp at(6), gp at(60), edge(C2:3, C1:1))
show fr2
C3 8 : gp at(6) : fr2

let pur1 = mp(C1, C2, C3) at(30)
show pur1 purple
let pur2 = mp(C1, C2, C3) at(3)
show pur2 purple
let pur3 = prz(ep(pur2, pur1, 0.25), C3:8)
show pur3 purple
C4 3 : pur3 : pur2

let or1 = mp(C3) at(56)
show or1 orange
let or2 = fred(pur3, or1, edge(C4:3, C4:61))
show or2 orange

C5 8 : pur3 : or2
P1 1 @ [45.3667] : mp(C1) - girdle
P2 3 @ [44.193] : gp
P3 2 @ [44.596] : gp