Education
Colored Bands in CVD-Grown Diamond
Srushti Tanti and Raju Jain

Figure 1. A growth remnant appeared as a color band (arrow) in a 3.14 ct CVD-grown diamond. Photomicrograph by Raju Jain; field of view ~11.75 mm.

Figure 2. A: Hazy parallel lines (indicated by arrows) resembling whitish internal graining. Photomicrograph by Raju Jain; field of view ~6.31 mm. DiamondView imaging of the pavilion facets showed blue growth layers in green fluorescence (B), as well as strong green phosphorescence (C). Images by Suraj Maurya.
The Surat laboratory recently examined a 3.14 ct F-color oval brilliant diamond grown by chemical vapor deposition (CVD). The diamond featured a single dark brown band measuring ~2.2 mm in length that resembled graining in natural diamond (figure 1). The band was visible under the microscope as well as with a 10× loupe. The clarity grade was VVS2 based on this colored band, which was visible through multiple bezels and affected the transparency at that location. Through the pavilion, parallel whitish bands were also observed (figure 2A).

Figure 3. False-color PL map of the SiV– defect at 736.6/736.9 nm using 633 nm laser excitation, normalized to the diamond Raman area on the pavilion. The dashed line indicates the approximate outline of the diamond.
The subtle banding seen in this diamond differed from a cloud of graphite inclusions at a growth interface previously reported in a CVD-grown diamond (Summer 2023 Lab Notes, pp. 213–214). The fluorescence image collected by the DiamondView revealed a layered growth structure that did not coincide with the color banding, indicating a start-stop cycling growth process typical of CVD synthesis (figure 2B). Deep UV fluorescence with green and blue coloration as well as strong green phosphorescence seen in the DiamondView image (figure 2C) indicated high-pressure, high-temperature treatment. The SiV– defect at 736.6 and 736.9 nm, a common feature of CVD laboratory-grown diamond and only rarely seen in natural diamond, was observed in photoluminescence (PL) spectra using 457, 514, and 633 nm laser excitation. PL mapping (figure 3) revealed that the concentration of SiV– was higher near the culet of the pavilion and dramatically lower near the table.
GIA has documented growth remnants in thousands of CVD-grown diamonds. But with a multitude of manufacturers, recipes, and treatments, a wide variety of clarity characteristics are encountered, including the unusual color band observed here.
Authors: Srushti Tanti is an analytics technician, and Raju Jain is a training specialist, at GIA in Surat, India.
This article was contributed by GIA® (Gemological Institute of America®)
GIA.edu | GIAindia.in
Education
IIG Demonstrates the Future of Industry-Ready Education at Jaipur Jewellery Show 2025
Through immersive industry exposure, factory visits and live design showcases, IIG redefined professional learning beyond the classroom at JJS 2025.
As the Jaipur Jewellery Show (JJS) concluded what is traditionally the final major trade exhibition of the year, the International Institute of Gemology (IIG) used the moment to underline a larger shift underway in professional education, one where classroom learning is no longer sufficient without deep, structured industry immersion.
For IIG students, JJS was not an event to attend but a system to decode. Through its Student Delegation Activity, the institute designed a multi-layered learning experience that combined trade exposure, manufacturing insight, design validation, and cultural context, positioning education as an ecosystem rather than a syllabus.
At the Jaipur Jewellery Show, students engaged directly with the B2B marketplace, studying contemporary Polki and Jadau collections, heritage jewellery from Bikaner, and emerging gemstone formats showcased by leading jewellery houses including Shiv Narayan, Valentine, Saanre, Mrs Marquise, Raanisaa, B.G. Jewellers, among others. The exposure allowed students to understand how design, craftsmanship, sourcing, and commercial viability intersect.
Beyond the exhibition, IIG curated industrial visits that revealed the operational backbone of the jewellery business. Factory visits to Valentine and Achal Jewels Pvt. Ltd. gave students end-to-end visibility into jewellery creation, from design development to Polki Jadau manufacturing and final quality control, while RMC Gems offered insight into international-scale gemstone cutting and polishing operations catering to global brands.
Design education also held a strong presence during the Jaipur programme. At the Jaipur Jewellery Design Festival (JJDF), IIG students presented their manufactured master’s project pieces, offering industry audiences a view into how design thinking is translated into production-ready jewellery.
The institute’s design capability also found recognition at the IJ Design Awards 2025, an evening that marked the elevation of jewellery as a serious art form through exclusive, finely manufactured creations. Among the finalists was Rabiya Malik, an international IIG online student, who secured a place among the Top 5 nominations in the GIA Emerging Designer of the Year category, once again highlighting the institute’s growing global footprint and the credibility of its learning outcomes across geographies.
The visit to the Amrapali Museum and the atelier of Sunita Shekhawat blended heritage with contemporary learning. In a discussion with Digvijay Singh Shekhawat, the industry’s recognition of IIG’s practical, ground-level training was evident, with interest expressed in future internship opportunities for IIG students.
IIG’s growing relevance lies in its ability to offer a complete learning ecosystem. With a diverse portfolio of courses that allows designers to study gemology, creatives to understand merchandising, and entrepreneurs to build retail and business capability, the institute has recently expanded into advanced business and retail boot camps covering branding, technology integration, AI, and experience-led retail strategy. These are complemented by RD Consultancy service, enabling students and alumni to seek guidance on business setup, expansion, and critical decision-making at a discounted rate.

Reflecting on the evolving nature of education, Rahul Desai, CEO & Managing Director, International Institute of Gemology, said, “Earlier, classrooms were enough. Today, education demands equal exposure to industry, process, culture, and decision-making. Immersive experiences like JJS are central to how we prepare students for real careers.”
As the year closes, IIG’s Jaipur immersion stands as a case study in how professional education must evolve, rooted in heritage, aligned with industry, and designed for the realities of modern business.
-
National News3 hours agoKISNA Diamond & Gold Jewellery launches KISNA Digital Gold in partnership with SafeGold, expanding its omnichannel gold ecosystem
-
National News2 minutes agoiAMORY Goes Mobile: D2C Jeweler Debuts App to Disrupt India’s ‘Counter-Led’ Retail
-
ShowBuzz2 hours agoAsia’s Premier Jewelry Hub Returns: 73rd Bangkok Gems & Jewelry Fair Set to Outshine Record-Breaking Predecessor
-
ShowBuzz55 minutes agoExperience A New Era of Diamond Jewellery at the revamped DP Jewellers Ujjain & Udaipur Branch


