Asscher Diamond Research Center
Data, sources and methods behind the site’s most important claims
What this section is for
The Research Center separates primary facts, editorial screening frameworks, and measured market observations. The goal is to make important claims auditable instead of hiding methodology behind generic “expert guide” language.
Core reference assets
Proportion Reference
What the report numbers can—and cannot—tell you about an Asscher.
Size & Millimeter Reference
Transparent face-up width reference ranges with provenance and limitations.
Asscher Price Index
The measurement framework for future reproducible natural and lab-grown price observations.
Source system
The primary-source bibliography records the authoritative materials used for grading terminology, the limits of fancy-shape cut grading, carat weight, color, clarity and Asscher history. Individual guides should cite the most relevant source directly instead of relying on a generic site-wide references statement.
How to read our evidence labels
| Label | Meaning | Example |
|---|---|---|
| Primary-source fact | Directly supported by a grading laboratory, standards body or first-party historical source. | GIA gives overall cut grades to standard round brilliants, not fancy shapes. |
| Editorial screening range | A practical comparison band used to narrow candidates; not a laboratory cut grade. | Near-square 1.00–1.05 L/W as a classic Asscher starting point. |
| Reference range | A planning range assembled for comparison and explicitly labeled approximate. | Typical face-up widths by carat. |
| Measured market observation | A dated dataset with documented filters, sample count and statistic. | A future Asscher Price Index release. |
Current evidence status
| Reference | Current status | What is reproducible |
|---|---|---|
| Proportion reference | Editorial screening framework | Source-backed GIA cut-grade limitation + explicitly labeled house screening bands |
| Size & millimeter reference | Editorial planning reference | Versioned six-band CSV, labels, notes and unchanged values |
| Price observation framework | No measured index published | Downloadable raw-observation schema, cohort rules and publication thresholds |
Research principles
- Never call an editorial proportion band an official “GIA Ideal Asscher” standard.
- Keep Royal Asscher—the company and patented branded cut—distinct from generic Asscher/square-emerald market terminology.
- Separate carat weight from face-up size; carat is weight, not diameter or width.
- Preserve observation dates for prices and retailer inventory claims.
- Correct or retire data when the supporting method can no longer be reproduced.