Bonhams 2017 Fall Jewelry Analysis: The $8 Brooch Sells

A busy weekend for me. Lots of auctions coming up but let’s finish our look at the auctions last week. I plan to make this a shorter analysis. I am not including a past auction of Bonhams to compare. Bonhams removes the unsold items from its list after the auction so if you do not gather your data before that then it is harder to get. My plan then is to focus on this auction only. I will look at the stats and percentage of sold versus unsold lots. Next, we will look at the top performing items and then look at the highlights from the post last week.

Sold versus Unsold

Note my results do not include buyer’s premium.

Looking at the table below you can see the percentage sold and unsold by category (type). There were 180 lots up for auction. The types are in order by highest percentage sold.

I also listed the total lots in each category so you get an idea how much was for sale. Watches did well but there were only 4. Same logic can be applied to the worst performing categories that only had 1 lot up for sale in that category. The category with the most items was the Ring category. From the Skinner analysis, we saw rings did well in that auction too.

Let’s dive a bit deeper into the items. Below is the table with the mean, median, and mode. I describe the significance of using these metrics in the Skinner analysis.

The lots ranged from $2,000 to $1,500,000 for the high estimate. So it is no surprise to see the average be so far off from the median and mode. Those higher end products can throw off the average. We see that most items were around $10,000 and sold at or slightly (10%) above the estimate.

Were there any outliers? What were the best performing lots?

Top 5 Lots

I like to look at the lots that outperform their estimates, not look at the lots that made the highest sale. Sometimes those are the same as we saw for that emerald brooch at Skinner. This time that was not the case. There were no major outliers. I created a table of the top 5 lots that were above their high estimate.

It is a good mix of designer and early 19th century that made the list. Below are the first 3.

Diamond and ruby line bracelet from 1925 was estimated to go between $5,000-$8,000. It sold for $20,000.

The emerald diamond ring sold for $22,000 and was estimated between $6,000-$8,000.

This fine diamond pendant from 1910 was thought to go between $8,000-$12,000 and sold for $28,000.

Past Predictions

So what about the items we looked at last week?

The wooden gold brooch by Cartier…

and the black opal that was estimated around $300,000.

Both went unsold. I was surprised about the brooch, it was estimated between $10,000-$15,000. Which I did not think was that bad.

Now to the final piece the story of the yard sale brooch bought for $8 and sold for…

$21,000. Bonhams predicted that right. They estimated getting between $20,000-$30,000.

All photos courtesy of Bonhams.

What are your thoughts on this auction? Do you agree with my findings? What was an item you were watching in this auction? The coming week is going to be fun! I will look at two celebrity auctions based in London. Check back this week for more on Data in the Rough!




Skinner Fall 2017 Fine Jewelry Analysis: The Emerald Outlier

Skinner Fall 2017 Fine Jewelry Analysis: The Emerald Outlier

Week one is done of my auctions schedule. I know I was excited to see the results from the week. There were plenty of ways to look at the data from the Skinner Auction and I confess I took a bit longer trying to see what the best story to tell would be. So, after different ways of dissecting the results I am structuring the article to focus first on the mean (average), median (the middle value of the data) and the mode (the number that is repeated most often) with the % breakdown of the types of items sold vs unsold. Then look at our predictions from the last article and finally the stand out piece in the auction.

Items to remember I used results for both September 2016 and 2017 that do not include buyer’s premium. If the item was withdrawn I considered that unsold.

Sold vs Unsold

For both September Fine Jewelry auctions at Skinner, the percentage was the same, roughly 81% of the lots sold, leaving 19% of the lots unsold. But did the same percentage of items sell in each category (type)? Many did stay the same.  Let’s look at 2017.

Now 2016. I have the categories arranged by highest percentage sold in each category.

I have bolded 2 categories of interest the rings and watches. In 2016 there were 18 watches on auction and 2/3 of them sold. For the 2017 auction there were 11 and 9 sold. I have been reading about trends in the watch industry. I will dig a bit deeper on my own to see about the designers and make. Those numbers though of the count are small. Rings are a bit higher in amount of lots. In 2016 there was a total of 113 auctioned. In 2017 the total was 94. As you can see this auction had great luck on selling rings, 88 were sold! I have not seen as much out on rings trending but it may be something to keep in mind.

So now for the statistics. Last year had over 300 more lots on auction versus this year. Skinner ended up getting a large collection to sell from a museum, I enjoyed viewing the lots and lost a bid for some earrings.

I looked at the data two ways, what were the statistics for the high estimates on the lots and of the lots sold how many times did they go above the high estimate? That calculation was the result $/high estimate.

Looking at the table above we see 2017 had items that had a higher estimated value given to them than last year. The same for median and mode. So higher estimated items in 2017 than last September. What about the results? Looking at the amount above the high estimate it looks like the auctions are about the same. The average says that the auctions had their items make the high estimate. This is why I like the other two metrics. The median shows that the results are less than the estimate. To get the median I arranged the numbers from lowest to highest and went for the item in the middle, or if it is an even number the average of the two middle numbers. The mode looks at the highest number of times the item is listed. So highest amount of lots for 2017 sold for 30% less than what Skinner predicted. In 2016 that number is 20%. Even though the amount per item was lower in 2016 the results were a little better.

Past Predictions

If you read my post last week I had 2 items that I was following. Those were the natural pearl pendant selling between $50,000-$75,000 and the Georg Jensen pieces.

Natural Pearls

The pendant from my last post.

The pendant did not sell. What does that mean in the auction world? Are we seeing a decline in interest? That pearl was not the only one on sale. Lot 383 an Antique Natural Pearl and Diamond Necklace, estimated to go as high as $15,000; sold for $29,000. Almost twice the estimate. The pendant may have been priced too high or there was a flaw that was not disclosed.

Georg Jensen

This designer did better than the pearls. Below are all the Jensen lots that were in the 2017 auction.

Only one Jensen item didn’t sell and 6 of the 10 sold above the high estimate. Here are the top 2 Jensen items.

.830 Silver and Amber Brooch, Georg Jensen

.830 Silver, Amber, and Green Onyx Necklace, Georg Jensen

Now let’s see how Jensen did with the other items. Below is the table for the top 5 items above estimate. Some items tied so more than 5 items are listed.

You see lots 7, 11, 10 all are Jensen. I think this Danish designer is still hot on the auction block. Wait, does that look like a typo, a lot did 10 times better than estimated? Yes, it did. If listed correctly, I checked the catalog and online, the last lot 384, an antique emerald brooch was the stand out piece of the auction.

The Emerald Outlier

This piece was listed to sell between $7,000-$9,000 and its final price was $90,000 (not including buyer’s premium)! What a way to end the auction!

I saw this small piece at the preview.

The emerald measured 9.55 x 9.50 x 4.65 mm and the brooch was less than an inch long. The interest lines in the origin of the emerald, it was a certified Colombian emerald, the finest you can get. Fun fact the emerald brooch and pearl necklace belonged to the same owner, Natica Inches Bates Satterthwaite. A native New Englander whose father worked at Harvard University. She passed away in 2015.

What did you think of my auction recap? Anything you’d like to point out or comment on? Next is a quick recap of Bonhams then more auctions to look forward to on Data in the Rough! Photos except the first one are courtesy of Skinner Auction.




Skinner Fine Jewelry Auction: June 2017 Analysis

Back for part two of my analysis of the Skinner Fine Jewelry Auction of June 2017. If you missed my highlights from the Susan Freeman collection that was a part of the June fine jewelry auction, click here.

The results are in! This article will look at how Freeman’s collection of % sold did against the other items in the Skinner auction for this year and last year. Then I will look at what the regular items did by category and see the bottom 6 and top 6 of the auction.

This year versus last year

In my last analysis, we saw that the lots sold were 68% and unsold were 32 % for the Freeman collection. Below a chart of sold and unsold lot % for the 2016 and 2017 June Fine Jewelry Skinner Auctions.


Freeman’s lots are included in the chart for 2017. You see the bars to the left is the % for 2016 84% sold. The right has this year which is a little lower at 83% sold. If the 14 unsold lots had been sold from the Freeman collection, this would only bump that number up to 86% sold, not a major change from last year. Had all of Freeman’s lots been removed from the auction the sold rate would be at 85%. Even though her collection did not perform as well as the average it did not have a significant impact on the % sold versus last year.

What didn’t sell

So then what categories did not perform as well for the items that did not belong to Freeman. Below a table that does not include the Freeman Collection. The total lots on auction were 413; 37 were Freeman’s leaving us with 376 regular lots at auction.Table-Skinner-June-Fine-jewelry-2017

The category with the most lots were rings at 108 lots. 90% of them sold. The lots in the same category as necklaces and earrings were the lowest performers with only 78% and 76% selling. Without making the article too long and tedious the categories can be drilled down to see if for example studs sold less than long earrings etc. but I am just showing a high-level view for your interest. The categories are not as important as seeing what big ticket items did not sell. For example, which would you rather have if you were employed by an auction house, 3 pairs of earrings estimated to sell for $500 each that do not sell or a ring estimated for $10,000 that is not sold? For me, the later would be worse because more money is lost to me than if the former scenario happened.

The top 6 unsold items by their estimate below:


Hard to believe the Bulgari and Van Cleef & Arpels pieces did not sell. Do you think it was due to the cost, lack of interest, or the design was not pretty enough? As I work more with auction data I will hopefully have a better answer for that.

So, what did better than expected?

King George

A list of the top 6 sold items that performed better than their high estimate. This is different than top selling items by price. If you want that go to the Skinner results and sort by that. I am hoping to dig a little deeper with this data.


For this auction, it was all hail King Georg Jensen! 5 of the 6 pieces did better than estimated. All these pieces were signed. I feel there may be a trend for well-made silver jewelry emerging. I have seen Jensen do well at auctions but time will tell if this will be a designer whose pieces are increasing in value at the auction block.

I hope you enjoyed my auction analysis for the June Skinner Fine Jewelry. Return soon for more from Data in the Rough!