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Cutting and Polishing

Figures [Round Brilliant Facets]  [Different Cuts]

1. Oldest technique

a. Romans--rough diamond crystals

b. Middle Ages--first faceted diamonds

1) Chipping and grinding

2) Cleaving

3) Bruting--two diamonds rubbed together

4) Polishing

a) About 1300-1900, no real advance in cutting

i. Slow rubbing on wooden or copper file charged with diamond powder.

ii. Fe wire with diamond dust and olive oil.

iii. Cutting design

b) About 1900

i. Major advance--diamond rotary saw.

ii. Able to cut two stones from well-formed rough.

iii. Precision faceting.

2. Cutting process

a. Evaluate stone

1) Color

2) Clarity

b. Sawing

1) Diamond mounted in dop.

2) Rough shape sawed with diamond dust and oil.

c. Cleaving--only used when sawing not practical.

d. Bruting, girdling, rounding up, or cutting

1) Only brilliant or mixed cuts.

2) Not with step cuts where the stone's outline is rectangular or square.

e. Faceting

1) Facets (diagram)

2) Blocker, lapper, lopper - person.

a) First cuts table and culet.

b) Second step cuts the crown and pavilion facets.

3) Finisher, brillanteerer = person

a) Polishes star and girdle facets.

b) Does minor corrections. Weight yield from the rough (uncut stones)

1) Fancy cuts

a) Fancies are all shapes except round.

b) Often cut due to odd-shaped rough.

2) Thin rough

a) Fancies

b) Rounds with "spread stone"

i. Larger girdle diameter

ii. Appear larger

3) Cutting for more carat weight (i.e., more money)

a) Large table with same crown angle

b) Thick girdle

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