EditorsNov 07, 2025
Piece of the Week: An MVP’s Sapphire Tennis Necklace At the 2025 World Series, the Los Angeles Dodgers’ Yoshinobu Yamamoto sported a custom necklace made by California retailer Happy Jewelers.
GradingDec 17, 2018
Lab Group Updates Padparadscha Requirements, Treatment Vocab
The Laboratory Manual Harmonisation Committee clarified on a disqualifying trait for padparadscha sapphires and how lab reports should address new corundum treatments.
Lucerne, Switzerland—The Laboratory Manual Harmonisation Committee has further harmonized the color description for padparadscha sapphires and vocabulary regarding new treatments on lab reports.
The LMHC recently had its 29th meeting, hosted by Gübelin Gem Lab in Lucerne, Switzerland, on Nov. 14 and 15.
The committee currently is comprised of representatives from the Central Gem Laboratory (CGL), CISGEM Laboratory, DSEF German Gem Lab, Gübelin, the Gemological Institute of America, the Gem and Jewelry Institute of Thailand (GIT) and the Swiss Gemmological Institute SSEF.
During the meeting, the first major point the labs agreed to clarify was the use of the term “padparadscha.” They deemed that the term can’t apply to a gemstone if the color is unstable and shifts to pink when exposed to a color stability test.
When asked why the LMHC wanted to clarify this point, Lore Kiefert, chief gemologist at Gübelin as well as host of the meeting and past co-chair of the LMHC, said the decision came after the SSEF discovered issues with the color stability of some padparadschas.
“If you buy a gemstone as a padparadscha and several days later it is a pink sapphire, you have probably overpaid, so we need to make a comment about the color stability,” she said.
The Laboratory Manual Harmonisation Committee said that corundum with an unstable color, as shown in this photo, is not qualified to be called “padparadscha.”
The LMHC currently defines padparadscha as a “a variety of corundum from any geographical origin whose color is a subtle mixture of pinkish orange to orangey pink with pastel tones and low to medium saturations when viewed in standard daylight.”
Kiefert said that definition won’t be narrowed any time soon, given that each market has its own perception of what comprises a padparadscha. As it is, she added, it already has taken a great amount of time to come to the current conclusion.
However they are looking into a color communication system to see if they can define the same borders for colors at all of their labs.
The LMHC also addressed issues raised by new treatments, including the low-temperature heating of corundum and a new sapphire heat treatment that has been incorrectly named High Pressure-High Temperature (HPHT) within the trade.
RELATED CONTENT: State of the Colored Gemstone Market: All Together Now?
In regards to the latter, the LMHC said current data available from member labs shows the treatment is essentially a form of heating and, as a result, is similar to most known heating techniques.
For this reason, it doesn’t require a specific reference on lab reports beyond the standard disclosure of heat treatments, though the committee did stress that heat treatments can create fissures or expand pre-existing fissures in a gemstone, especially when high temperatures are applied, possibly having a negative impact on the stability of the heated stone.
The LMHC said it also kicked off a project aimed at harmonizing the use of color descriptors and trade color terms at its member labs, though there is no additional information available yet regarding what that might include or what the timeline might be.
The LMHC also approved new info sheets about organic fissure-filling in gems and hydrophane opal. Kiefert said the two sheets were already in existence but were just now finalized.
The LMHC usually meets once per year and has tentatively set its next meeting for November 2019.
The ICA has scheduled its next Gemstone Industry and Laboratory Conference, addressing similar issues, for the 2019 Tucson gem shows.
The LMHC has no formal ties to any trade organization. The info sheets it creates are a result of harmonization attempts of its member labs and are also meant to help the trade understand the wording on LMHC member reports. They also are meant to serve as recommendations for other labs that may come across the same issues.
All LMHC info sheets can be accessed on its website.
More on Grading
The Latest
IndependentsNov 07, 2025
Foundrae’s New Palm Beach Location Is a ‘Golden Solarium’The brand’s seventh location combines Foundrae’s symbolic vocabulary with motifs from Florida’s natural surroundings.
FinancialsNov 07, 2025
Watches of Switzerland’s H1 Sales Up 8%The retailer also shared an update on the impact of tariffs on watch customers.
Brought to you by
Jewelers of America Aligns New Mission to Create Meaningful Impact for MembersFrom educational programs, advocacy, and recent MJSA affiliation, Jewelers of America drives progress that elevates businesses of all sizes.
SourcingNov 06, 2025
Pink Tourmaline Bracelet, Emerald Suite Take Top Spectrum Honors Pink and purple stones were popular in the AGTA’s design competition this year, as were cameos and ocean themes.
Weekly QuizNov 06, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
IndependentsNov 06, 2025
Greenwich St. Jewelers Hosts Raffle Supporting Food RescueAll proceeds from the G. St x Jewel Boxing raffle will go to City Harvest, which works to end hunger in New York City.
IndependentsNov 06, 2025
Cornell’s Jewelers Names New PresidentCourtney Cornell is part of the third generation to lead the Rochester, New York-based jeweler.
SourcingNov 06, 2025
De Beers’ Production, Sales Increase in Q3 De Beers also announced more changes in its upper ranks ahead of parent company Anglo American’s pending sale of the company.
WatchesNov 05, 2025
Shinola President Steps Down Just as He Starts Former Signet CEO Mark Light will remain president of Shinola until a replacement for Ulrich Wohn is found.
AuctionsNov 05, 2025
Taylor Swift’s Engagement Ring Designer Makes Her Auction DebutKindred Lubeck of Artifex has three rings she designed with Anup Jogani in Sotheby’s upcoming Gem Drop sale.
FinancialsNov 05, 2025
Pandora Posts Modest Q3 Sales Growth Amid ‘Weak’ Consumer Sentiment The company focused on marketing in the third quarter and introduced two new charm collections, “Pandora Talisman” and “Pandora Minis.”
FinancialsNov 05, 2025
Brilliant Earth’s Q3 Sales Climb 10%The jewelry retailer raised its full-year guidance, with CFO Jeff Kuo describing the company as “very well positioned” for the holidays.
Policies & IssuesNov 04, 2025
Supreme Court to Hear Tariffs Case WednesdayAhead of the hearing, two industry organizations co-signed an amicus brief urging the court to declare Trump’s tariffs unlawful.
MajorsNov 04, 2025
Danny Clark to Become Stuller CEO, Succeeding Matt StullerStuller COO Belit Myers will take on the additional role of president, with all changes effective at the start of 2026.
ColumnistsNov 04, 2025
Peter Smith: What Do Birds Have to Do With the Price of Gold? Smith cautions retailers against expending too much energy on things they can’t control, like the rising price of gold.
TrendsNov 04, 2025
Amanda’s Style File: Fall Colors for November BirthdaysCitrine and topaz are birthstones fit for fall as the leaves change color and the holiday season approaches.
IndependentsNov 04, 2025
Weston Jewelers Heads to Fort LauderdaleThe family-owned jeweler will open its fourth store in Florida in late 2027.
CrimeNov 03, 2025
Men Dressed as Construction Workers Burglarize Jeweler’s Home The NYPD is looking for three men who stole a safe and jewelry valued at $3.2 million from the home of a jeweler in Jamaica Hills, Queens.
MajorsNov 03, 2025
Matthew Rosenheim Takes Over as JA Board ChairThe trade organization also announced its executive committee and five new directors.
CollectionsNov 03, 2025
Muse’s ‘Have a Heart’ Collab Returns, Now With DDGThe “Have a Heart x Diamonds Do Good” collection is championed by model and humanitarian Flaviana Matata and will benefit her foundation.
AuctionsNov 03, 2025
Kashmir Sapphire Ring Tops Christie's Online AuctionThe ring, set with a nearly 17-carat Kashmir cabochon sapphire, sold for $1 million.
TrendsOct 31, 2025
Piece of the Week: A Spinner Fit for ‘Frankenstein’This “Mother Father” spinner necklace from Heavenly Vices Fine Jewelry draws inspiration from Victorian Era jewelry.
CrimeOct 31, 2025
5 More Arrested in Louvre Heist, Jewelry Still Missing The suspects were rounded up in Paris and its suburbs on Wednesday night, but none of the stolen jewels were recovered with them.
Recorded WebinarsOct 31, 2025
Watch: How to Master Google Reviews for Your BusinessExperts share top tips on how to encourage positive reviews and handle negative feedback.
Supplier BulletinOct 30, 2025
Protect Your Customers and Your BusinessSponsored by the Gemological Institute of America
CrimeOct 30, 2025
29-Year-Old Man Charged in Multiple Seattle-Area Smash and Grabs The suspect faces charges in the August robbery of Menashe & Sons Jewelers and is accused of committing smash and grabs at two pawn shops.
