What a Laboratory Does—and Does Not Do

A laboratory report has great value precisely because its scope is limited. A professional laboratory does not answer every possible question about a diamond; it answers questions defined by the specific service and describes its findings according to the methodology and technology available at the time of examination.

For that reason, the most important question before reading a report is not simply “which laboratory?” but:

“What service did the laboratory perform, and what question was that service intended to answer?”

A laboratory service is a contract between a question and an answer

Different services may encompass:

• material identification;
• natural versus laboratory-grown origin;
• treatment detection;
• color origin;
• the 4Cs or another quality assessment;
• colored-diamond analysis;
• certain geographic-origin programs;
• an update, verification, or another limited procedure.

The fact that a laboratory can perform a particular analysis does not mean that the analysis is part of every report it issues.

[VISUAL 75.1: Laboratory service map—identification / origin / treatment / grading / geographic origin]

A submission claim is not a laboratory finding

A client may submit an item described as a “natural untreated diamond.” That is a claim made at submission. A laboratory finding arises only after examination.

This distinction may sound obvious, but it is critical to the professional reading of documentation. A report should distinguish:

• what the client claimed;
• what the laboratory examined;
• what the laboratory concluded;
• what was outside the scope of the service.

Identification and grading are not the same

Identification answers what the item is and, where relevant, its origin or treatment status.

Grading describes particular quality characteristics under the rules of a specific system.

A stone may be correctly identified even though a particular grading system is not applicable to it. Likewise, a numerical or letter grade does not resolve questions of ownership, provenance, or price.

A grade is not market value

A laboratory grading report is not an appraisal. It does not automatically provide:

• retail value;
• replacement value;
• liquidation value;
• auction estimate;
• resale value;
• expected investment return.

Value is a separate professional problem, addressed later in the book.

In its current terms, GIA expressly states that its report is not a guarantee, valuation, or appraisal and that it describes the item according to the techniques and equipment used at the time of examination.

[VISUAL 75.2: Grading report versus appraisal/value document]

A report is not a certificate of title

A laboratory can describe the stone submitted to it. It does not follow that the laboratory confirms:

• who the legal owner is;
• whether the item is stolen;
• whether it was lawfully acquired;
• whether it is subject to a lien or another legal encumbrance;
• who has the right to dispose of it.

An invoice, contract, estate documents, and ownership records belong to other systems of evidence.

A report does not automatically establish provenance or a chain of custody

A standard diamond grading report does not automatically reconstruct a stone’s path from the mine to its present owner. Provenance may include ownership history or association with a famous collection. Chain of custody describes the documented custody and transfer of an item.

Both topics will be addressed in Chapter 80. A laboratory report can be one element in the chain, but it is not the entire chain.

Geographic origin is not a standard field on every report

Geologic or geographic origin should not be assumed merely because a document bears the name of a well-known laboratory. Geographic-origin services have a specific scope, prerequisites, and evidentiary limitations.

For diamonds, this problem is especially demanding and is addressed in detail in Chapter 79.

A report describes a stone at time T

Diamond may be a very stable material, but the condition of an item can change through:

• recutting;
• repolishing;
• chipping;
• abrasion;
• laser drilling;
• fracture filling;
• another treatment;
• alteration or removal of an inscription.

Laboratory technology can also change. GIA’s current terms emphasize that a later examination may produce a different result because of changes to the item, methodology, or instruments.

Re-examination is not an admission of an earlier error

If a stone is re-examined after many years, the result must be interpreted in light of:

• the stone’s condition then and now;
• the technology available then and now;
• the definition of the service;
• the grading rules;
• possible interventions between the two examinations.

A difference between two reports does not by itself prove that one laboratory “made a mistake.”

Natural and laboratory-grown service architectures are not the same

Laboratory services for natural and laboratory-grown diamonds should not be assumed to remain identical. Their names, scope, grading methods, and report architecture may change by institution and over time.

GIA’s current model for laboratory-grown diamonds is a good example of this service-specific boundary, but the detailed Premium/Standard criteria, the colored-LGD service, and comparisons with IGI, HRD Antwerp, and GCAL by Sarine were already addressed in Chapter 54. The laboratory lesson here is that, before interpreting any report, one must first establish the exact service name, its date, and its scope; only then can the meaning of a particular field or assessment be determined.

A facsimile, PDF, and official record are not the same

GIA’s current terms warn that a facsimile, PDF, shared copy, or printed version is not the same as the current official record and may not contain the latest information.

But even an official current record is not, by itself, a physical match to the stone. This connects Chapter 75 with the preceding anti-fraud chapter without taking over the detailed matching discussion in Chapter 78.

A laboratory report is not a guarantee of everything about a stone

Professionals should reject statements such as:

• “the laboratory guarantees value”;
• “the report proves ownership”;
• “the report proves that the stone is conflict-free”;
• “the report guarantees its future resale price”;
• “the report confirms the stone’s entire provenance.”

Some of this information may be very important. It simply belongs to other systems of evidence.

“Not found” and “not tested” are not the same

One of the most important disciplines in laboratory work is distinguishing:

negative finding—the laboratory looked for a particular phenomenon within a valid scope and did not find it;

from

out of scope—the specific service was not designed to address that question.

A user must not treat a blank field or the absence of a comment as proof that something was tested and ruled out.

Independence is a governance question

The client generally pays for the laboratory service. The mere fact of payment is not evidence of bias. More relevant considerations are:

• methodological independence from the desired commercial outcome;
• standardized procedures;
• quality control;
• staff competence;
• management of conflicts of interest;
• transparently defined services and limitations.

A detailed comparison of laboratory systems belongs in Chapter 77.

The best way to read a report

A laboratory service can be read in six steps:

1. claim—what is to be verified;
2. scope—what the selected service actually covers;
3. examination—what types of analysis are applied under the laboratory workflow;
4. finding/grade—what the laboratory concluded;
5. limitations—what that conclusion does not mean;
6. open questions—ownership, value, provenance, compliance, or other topics that remain outside the report.

[VISUAL 75.3: Claim → scope → examination → report statement → limitations → open questions]

Chapter summary

• A laboratory answers questions defined by the specific service.
• A submission claim is not the same as a laboratory finding.
• Identification, grading, treatment analysis, and geographic origin are different functions.
• A grading report is not an appraisal or a formula for market value.
• A report is not proof of ownership.
• A standard report is not automatic provenance or a chain of custody.
• Geographic origin requires a dedicated program and does not follow from every diamond report.
• A report describes an item according to its condition and the technology available at the time of examination.
• A difference found upon later re-examination does not automatically prove an earlier error.
• Natural and laboratory-grown services may have different, time-variable report architectures; specific current models must be read according to the service name, date, and scope.
• An official record, a PDF, and a physical stone match are three different evidentiary layers.