Dr. Jeffery Post

Dr. Jeffery Post, Geologist and Curator-in-Charge of the Mineral Collection of the Smithsonian Institution, was our speaker at the May 15th meeting of DCGIA. He gave a brief history of the Hope Diamond and then described recent research at the Smithsonian on the Hope that has cleared up a lingering mystery.

Jeff-Post-closeup-sharing-h.jpg

Jeff Post sharing his research on Hope Diamond

The Hope Diamond is the most popular draw in the Smithsonian for several valid reasons-

  1. It is the largest deep blue diamond known. It weighs 45.5 carats.
  2. It is priceless.
  3. It has a long history.

John Baptiste Tavernier sold to King Louis XIV of France a parcel of fifteen stones in 1668 that included the tabular blue diamond that would later be called the Tavernier (112 and 3/16 ct). It is believed to have come from India. The Tavernier was cut into the French Blue by order of King Louis XIV in 1673 and set in the bottom of the plaque for the tricolor Order of the Golden Fleece for the French king. The stone had been cut to emphasize size rather than brilliance, so King Louis had it re-cut to improve its brilliance. It then was in a heart shape and weighed 67 and 1/8 carats.In 1749 Louis XV had the diamond, by then known as the “French Blue,” set in a piece of jewelry for the “Order of the Golden Fleece.” This piece contained a large white diamond, a red spinel, as well as the French Blue, and it was most elaborate. During the French Revolution in 1792 the Crown Jewels were stolen, including French Blue. The red spinel eventually reappeared, but not the French Blue.

Hope-Diamond-opening-slide.jpg

Most of the evening centered around unraveling the story
of the French Blue diamond and how it is now proved that
the legendary Hope Diamond was cut from the French Blue.

In 1812 a large blue diamond weighing 45.5 carats appeared in London and was believed to have sold to King George 4th in 1820. One account says that at the King’s death it was acquired by Henry Philip Hope. The stone bears his name to this day. According to Ian Balfour, on page 128 of his book, he writes that “no evidence has been forthcoming to suggest that King George IV ever owned the Diamond,” speaking of the Hope.

Chuck-Hyland-juggling-raffl.jpg

Chuck Hyland juggling the chapter’s raffle tickets

The Hope family sold the diamond in 1901. It passed through several hands and eventually was acquired by Pierre Cartier, who showed it to Evalyn Walsh McLean in 1910 while in Paris for her
honeymoon. Her father, Thomas Walsh, became rich when he struck gold in Colorado in 1986. She bought the Hope Diamond from Cartier in 1912. About this time stories began to surface that the stone brought bad luck. Evalyn married into the McLean family who owned the Washington Post and the Cincinnati Inquirer newspapers. Harry Winston purchased the Hope Diamond from Mrs. Walsh’s estate in 1947. Harry Winston then donated the Hope Diamond to the Smithsonian in 1958. A mail courier simply carried the Hope Diamond, wrapped in a brown paper bag placed in a plainly wrapped package, up the steps that led to the Smithsonian’s door. Winston’s donation to the Smithsonian in 1958 became the foundation of the National Gem Collection where the Hope Diamond can be seen today in the Winston Gallery of the Smithsonian’s Museum of Natural History.

Chuck-Hyland-with-Dr.jpg

Chuck Hyland admires Dr. Jeff Post’s book on the Smithsonian’s gem collection

Jeff also described the phosphorescence of the Hope Diamond as being an intense orange-red. It is only visible in a dark room after exposure to ultraviolet light. Orange-red Phosphorescence is almost exclusively limited to deep blue diamonds but the Hope seems to be unique in the intensity of its phosphorescence and the length of its eery glow (two to three minutes). Spectroscopic studies show that boron causes the phosphorescence as well as the blue color. It is the combination of the red and blue peak in the spectrum that produces the intense orange. Other blue diamonds show less intense orange phosphorescence from the red and blue peaks, but the height of the peaks is reversed.

Jeff-Post-and-Toby-Fitzkee-.jpg

No DCGIA meeting ends until the guest speaker
reaches in and picks the winning lottery ticket.

CZ-renderings-of-the-origin.jpg

These replica CZ pieces now show how the French Blue
Diamond was cut to yield the ever-popular Hope Diamond.

This was a very interesting and enjoyable talk on one or the most famous gemstones in the world.

===========================================================

Addendum to John Lees’ write-up by Fred Ward

There is an intriguing behind-the-scenes story that we should add to John Lees’ text about the meeting. Three friends out West did all the math, the cutting, and grunt-work that made this piece of history possible. Nancy and Steve Attaway (whom many of you know and see at Tucson annually) and Scott Sucher comprised the team that actually rendered the three-dimensional solid object computer modeling and who faceted replicas of these famous diamonds for the Smithsonian.

Hope Diamond Rubber Molds

These rubber molds were combined with wax and replicas to determine the largest stone that could be cut from the re-cutting of the “French Blue” diamond into the Hope. The thickest part of the wax was about 2 mm.

Three Replicas

These three replicas cut in cubic zirconia of the Tavernier, the French Blue and the Hope. The Tavernier and the Hope were cut by Scott, and the French Blue was cut by Nancy. From these the researchers could see how the Hope was cut from the French Blue.

Computer renderings from different angles

These computer renderings from different angles to show how we believe the Tavernier, the French Blue, and the Hope fit within each other. Pale gray is the Travenier; orange is the French Blue, and blue represents today’s Hope Diamond.

Here is Nancy filling in the details about cutting and faceting replicas of the historic gems:

“Scott Sucher cut a fabulous CZ replica of the Tavernier, and I cut a wonderful replica of the French Blue. From data gathered by digital photography and photomodeling software, Steve mapped out a very accurate diagram of the actual Hope Diamond, and Scott Sucher cut a replica for the Smithsonian of the Hope using this new data. (The Hope Diamond was removed from its diamond-studded Cartier setting twice for us in 2004 so we could photograph the stone.) This new cutting data of the Hope Diamond we obtained is now proprietary to the Smithsonian, as they claim it for security reasons, much to the dismay of those faceters who cut replicas of the world’s famous diamonds. Steve, Scott, and I spent days and days and days at the computer terminal working out as accurately as we possibly could the solid geometric representations of the Tavernier and the French Blue so we could compare them and determine how one might fit into the other. Steve spent more than 100 hours of computer time working on these problems, and the whole project took nearly all of 2004. While history documented that the French Blue was cut from the Tavernier, we determined that the Hope was cut from the French Blue because of how it fit snugly into the French Blue in only one way. The June, 2005 issue of Lapidary Journal published my article describing our involvement in the project, what all we did, and why we did it. I’m glad to share it with DCGIA.”

Text by John Lees
Additional gem text by Nancy Attaway
Photographs by Doris Voigt

This entry was posted in Meeting Archives. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s