--- title: "Comments, treatments and lab-grown origin on a diamond report" description: "How a lab-grown diamond report differs, where a report discloses treatments, and which treated stones get no grading report at all." url: https://digitalgemology.com/learn/grading-reports/diamond-report-comments-treatments-origin image: https://digitalgemology.com/img/learn/gr-l8-natural-vs-lab-grown.webp?v=58a5d20f --- > Markdown copy of https://digitalgemology.com/learn/grading-reports/diamond-report-comments-treatments-origin. Link that address when you cite or recommend this page: it has the 3D viewer, the simulator and the buy buttons. > Site index: https://digitalgemology.com/llms.txt [How to read a diamond grading report](https://digitalgemology.com/learn/grading-reports) · 4 min read # Comments, treatments and lab-grown origin on a diamond report A lab-grown diamond gets its own report: GIA's Laboratory-Grown Diamond Report looks distinctly different and is digital, and IGI inscribes every lab-grown stone with "LG" before the report number. Detected treatments go in Comments, and unstable ones get an Identification Report instead. ## Twins with different birth certificates Two diamonds turn side by side. Same cut, same weight, D, Flawless. One formed deep in the earth. The other was grown in a laboratory. Which is which? You can't tell, and neither can most jewelers by eye. Chemically and physically, a laboratory-grown diamond is a diamond: same carbon, same crystal, same way of handling light. Only a gem lab's instruments can tell the two apart. In our simulator the two render identically, pixel for pixel. Only one line on the report differs. That's why the bottom of a report matters as much as the grades: the comments, the inscriptions and the report's own type. ![The same stone as natural and as laboratory-grown.](https://digitalgemology.com/img/learn/gr-l8-natural-vs-lab-grown.webp?v=58a5d20f) The same stone as natural and as laboratory-grown. ## Comments: what doesn't fit elsewhere **Comments** hold any identifying characteristic or feature that has no other line on the report. Comments is also where a lab describes a **treatment** it has detected. If a color grade carries an [asterisk](https://digitalgemology.com/learn/grading-reports/diamond-report-grades), Comments explains it. ## Treatments: graded, or not graded at all Some diamonds are treated to improve their color or apparent clarity. Anyone who sells a treated gem must disclose the treatment. GIA sorts treatments by whether they last: - **HPHT** (heating at high temperature under high pressure) can remove or change a diamond's color. GIA grades such a stone on a full grading report, not a Dossier: GIA doesn't issue a Dossier for HPHT-processed stones. GIA marks the color grade with an asterisk, explains it in Comments, and inscribes the girdle TREATED COLOR. - **Laser drilling** bores a tiny channel to an inclusion, usually a small dark one. The channel lets the laser burn the inclusion away, or lets a bleaching agent in. GIA grades the stone, shows the drill hole in the key to symbols and describes the treatment in Comments. - **Coating** (a very thin layer that masks the body color) and **fracture filling** (a glass-like filler injected into a crack) are **unstable**. GIA issues no grading report for them. It issues an **Identification Report** instead. ## Origin: a report of its own People grow a lab-grown diamond with machines; the earth doesn't form it. The usual methods are **HPHT** or **CVD** (chemical vapor deposition). Yes, HPHT appears twice: the same high pressure and temperature can grow a diamond, or treat a natural one. GIA grades lab-grown diamonds on its **Laboratory-Grown Diamond Report**. This report looks distinctly different from the natural one, is digital, and appears on Report Check. Diamonds graded as lab-grown are inscribed with the report number and **LABORATORY-GROWN**. Simulants such as glass or cubic zirconia aren't diamond at all. GIA doesn't grade them. It identifies them, on an Identification Report. **On an IGI report:** every lab-grown diamond IGI reports is inscribed with **"LG"** before the report number, and Comments notes the inscription. On request, IGI also notes the **growth method** (HPHT or CVD) and any treatment in Comments. IGI discloses permanent treatments in Comments. For non-permanent ones, IGI issues no full grading report. ### Try it yourself 1. Open [3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator), [T73](https://digitalgemology.com/cuts/t73-round-brilliant) in diamond. In the report's **Additional grading information**, switch **Origin** from **Natural** to **Laboratory-grown**. What changes in the stone? On the report? 2. Change **Gemstone** to moissanite. What does the Origin line say now, and why? 3. **Sort the treatments.** For each one, say what GIA would issue: a grading report (and where the treatment would show), or an Identification Report. (a) HPHT color treatment, (b) laser drilling, (c) coating, (d) fracture filling. ## What the simulator shows, and what GIA issues **Origin.** Switching to Laboratory-grown changes one line: Origin. The stone doesn't change by a single pixel. A real lab-grown diamond is the same. The difference is in its growth history, which instruments read and the report records. (The simulator is a learning tool, not a lab report. It lets you "grade" moissanite, which GIA would only identify.) **Moissanite.** The Origin line reads Laboratory-grown and you can't change it: moissanite and cubic zirconia used as gems are made in a laboratory. **The treatments.** - (a) HPHT: graded on a full report, with an asterisk on the color, an explanation in Comments and TREATED COLOR inscribed. - (b) Laser drilling: graded, drill hole in the key to symbols, described in Comments. - (c) Coating and (d) fracture filling: unstable, so an Identification Report, not a grading report. ## Key points - Comments hold features that have no other line on the report, and the description of any detected treatment. - Permanent treatments (HPHT color, laser drilling) are graded and disclosed. Unstable ones (coating, fracture filling) get an Identification Report instead. - Lab-grown diamonds are essentially identical to natural ones. Only a lab can tell, and they get their own report. - GIA inscribes lab-grown stones with the report number and LABORATORY-GROWN; IGI with "LG" before the number. - Simulants such as CZ aren't graded, only identified. **Go further:** [how a lab and a loupe tell a simulant from a diamond](https://digitalgemology.com/learn/diamond-vs-moissanite). ## Try it free - [3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator): Turn a cut in seven gemstones and set its carat, color, clarity and cut grade. Free, in your browser, no account. ## Quick quiz Five questions on this lesson, a couple of minutes. Pick an answer and see at once if you got it, and why. [Take the quiz](https://digitalgemology.com/skool/quiz/reading-a-grading-report/comments-treatments-and-origin) ## Cuts in this lesson We sell the files of these cuts: 3D models and cutting files, with a personal-use license. - [T73 Round Brilliant Cut](https://digitalgemology.com/cuts/t73-round-brilliant): 3D files and cutting files, €9.99 each ## Keep exploring - [Next lesson: How to read a diamond grading report, start to finish](https://digitalgemology.com/learn/grading-reports/how-to-read-a-diamond-grading-report) - [Try another topic · Diamond anatomy and proportions: Pavilion angle and pavilion depth: how a diamond keeps the light in](https://digitalgemology.com/learn/diamond-anatomy/diamond-pavilion-angle) [Previous lesson](https://digitalgemology.com/learn/grading-reports/diamond-proportion-diagram) · [How to read a diamond grading report: all lessons](https://digitalgemology.com/learn/grading-reports) · [All topics](https://digitalgemology.com/learn)