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Figure 1. The “Infinite Blue,” an 11.28 ct Fancy Vivid blue diamond, sold for $25.3 million in Hong Kong. Courtesy of Sotheby’s.

Fall 2023 Auction Highlights

Erica Zaidman, January 26, 2024

Large blue and pink diamonds were among the top lots of the fall auction season, including the most expensive auction jewel of 2023.

Figure 1. The Bulgari Laguna Blu, an 11.16 ct Fancy Vivid blue diamond, was featured for the first time at auction in Geneva. Courtesy of Sotheby’s.

Spring 2023 Auction Highlights

Erica Zaidman, August 4, 2023

After a slow start, the spring 2023 auction season ends with multiple broken records.

Large sunstone rough from the Ponderosa mine in Oregon

Ponderosa Sunstone Update

Duncan Pay, May 11, 2018

John Woodmark provides an update on the Ponderosa sunstone mine in Oregon.

Figure 1. Left: The mother shell (<em>Mercenaria mercenaria</em>) and an 18K gold ring featuring a 14.43 × 14.63 mm lilac quahog pearl. Right: A rare collection of round quahog pearls ranging from 5.65 to 12.33 mm in diameter and in colors from white and beige to deep purple and tan. Photos by Robert Weldon; courtesy of ECIJA.

Exceptionally Rare Pearls from ECIJA

Si Athena Chen and Chunhui Zhou, May 23, 2023

An impressive variety of natural, wild, nacreous, and non-nacreous pearls were on display at the GJX show.

The increasing popularity of cultured pearls with unusual color and size combinations

Cultured Pearl Update

Duncan Pay and Jennifer-Lynn Archuleta, May 11, 2018

Fran Mastoloni shares his thoughts on the status of the cultured pearl market.

Figure 1. The 11.15 ct Williamson Pink Star is set in an 18K pink and white gold ring, along with 1.41 carats of trapeze-cut diamonds and 0.14 carats of brilliant-cut pink diamonds. Courtesy of Sotheby’s.

Fall 2022 Auction Highlights

Erica Zaidman, January 25, 2023

A successful spring season set high expectations for colored diamonds at auction in late 2022.

Namak Mandi: A Pioneering Gemstone Market in Pakistan

Habib Ur Rehman, Bilal, Syed Owais, Obaid Ur Rahman, and Andy H. Shen, September 3, 2021

Documents Namak Mandi’s transformation from a salt market to one of Pakistan’s primary gem trading centers, with a look at the commercial activities taking place today.

Measurement and Characterization of the Effects of Blue Fluorescence on Diamond Appearance

Yun Luo, David Nelson, Troy Ardon, and Christopher M. Breeding, September 3, 2021

Using customized, image-based measurement systems to quantify the effect of fluorescence on the color, brightness, and transparency of gem diamonds viewed in both face-up and table-down orientations.

A fleur-de-lis motif tiara set with cushion-cut, pear-shaped, rose-cut, and round diamonds.

A History of European Royal Jewel Sales, Including Sotheby’s 2018 Auction of Marie Antoinette’s Jewels

Russell Shor, January 22, 2021

Chronicles important auctions of jewels from European royal collections over the years, with a focus on a recent high-profile sale of items that once belonged to Marie Antoinette.

A group of rings featuring alexandrite from Brazil

Geographic Origin Determination of Alexandrite

Ziyin Sun, Aaron C. Palke, Jonathan Muyal, Dino DeGhionno, and Shane F. McClure, January 31, 2020

The geographic source of this rare color-change gem has a significant impact on value. Trace element chemistry profiles allow GIA to accurately determine origin for alexandrite from several countries.

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