In this guide
Identify the actual gemstone and provide its measured dimensions, contour references and intended setting method before approving a seat. Carat weight and a nominal diameter do not define the full geometry of a stone. A convincing rendered fit can conceal an incorrect depth, girdle relationship or bearing.
Start by agreeing who measures the stone and who reviews the metal interface. Preserve the stone identifier so a later substitution cannot silently reuse the previous seat approval.
Separate identity, size and contour
Record the stone’s length, width and depth with units and a measurement method. Add the views or source geometry needed to explain its outline, pavilion and relevant irregularities. Label a generic calibrated-stone model as a placeholder until it has been compared with the stone intended for use.
| Input | Why it matters | Question for the setter |
|---|---|---|
| Stone identifier | Prevents substitution ambiguity | Is this the stone being reviewed? |
| Length, width, depth | Establishes more than a face-up span | Which features control the seat? |
| Contour reference | Explains shape at the contact region | Does the proposed bearing fit? |
| Setting method | Changes the relevant metal geometry | What bench work remains? |
GIA’s setting quality benchmark discussion emphasizes the relationship between a bearing and stone contour.1 The practical handoff is therefore a specific stone-and-setting review, not a universal gap value copied into every design.
Define the CAD review question
Ask whether the model is intended to show appearance, reserve space for later cutting or represent a proposed finished interface. These are different states. Identify the metal left for bench adjustment and the source features that should remain fixed.
Do not enlarge the stone to make a render look tighter. Keep material geometry and gemstone geometry distinguishable. If the stone is not yet sourced, record the unresolved selection and the event that will reopen the seat design.
Review access as well as fit
Inspect the location and approach needed for the intended setting work. A seat that appears correct in a section may leave inadequate access for the actual operation. Include neighboring stones, decorative features and wearer-facing geometry in that discussion.
Request a clear issue location and proposed correction from the bench reviewer. “Needs more clearance” should identify which interface and why. Do not translate it into an arbitrary whole-ring scale change.
Close the loop on the physical sample
Link the printed or cast sample to the reviewed source and actual stone. Record the bench observations and any alterations made during setting. If the workshop modifies the geometry, capture the change so the next repeat order does not start from an obsolete CAD assumption.
The seat measurement worksheet records inputs, questions and decisions without prefilled approval. Pair it with the jewelry source-format guide and manufacturing handoff checklist.
Rendora’s jewelry tool entry helps organize supplied model and manufacturing evidence. Gemstone geometry, setting access and bench acceptance need their identified reviewer; a material preview does not establish stone security.
Can two stones with the same nominal size share a seat?
Treat that as a question for the measured contour and setting method. Confirm interchangeability rather than assuming it from the catalog size alone.
Should every change reopen the setting review?
Reopen it when the stone, bearing, surrounding metal or relevant access changes. Preserve the reason and affected revision.
References
- GIA, Avoid stone loss with quality assurance benchmarks, reviewed October 26, 2026.
About this guide
Rendora publishes practical guides for teams working with configurable 3D assets and traceable production handoffs. Updated October 27, 2026.