Good resources for 18th century gem prices?

[Devora]

My web searching has come up dry and I'm not sure where to start looking cuz I need to conceptualize a necklace for a story I'm writing but I need to be realistic as to what gems would be put on a specific kind of necklace.

The base metal I'm thinking of using is pewter but it will be a high-end pewter because I did read that the low-end stuff tended to be contaminated with lead alloys.

 

[Prince of Spires]

A quick search gave me this:

Historical Study of Gem Prices from Sydney H. Ball (1877- — Pala international

www.palagems.com

 

[Devora]

A quick search gave me this:

Historical Study of Gem Prices from Sydney H. Ball (1877- — Pala international

www.palagems.com

I've seen this article and I'm not looking for a history of gem values I'm looking for basically something like a spreadsheet of the prices gems would have back in the 1700s

 

[CupofJoe]

Then I think you really need to get specific.
What gems?
What year of the 18C?
Where in the world are you?
And probably a whole lot of other things.

 

[Mad Swede]

I've seen this article and I'm not looking for a history of gem values I'm looking for basically something like a spreadsheet of the prices gems would have back in the 1700s

I think you need to do some serious research into gems and jewellery, because the question you're trying to answer is far more complex than you seem to think. More than that, the article you have disregarded gives you some answers to part of your question.

First, uncut gemstones are generally priced per carat, where a carat is a measure of weight. For the period you're looking at there is no formally defined international measure for a carat, but you won't go far wrong if you assume that 1 carat = 250mg. (Note that the modern definition, fixed in 1907, is 1 carat = 200mg.) The price of each individual uncut gemstone depends on its size and whether there are any flaws present in the uncut stone. As a general rule for the period you are looking at, the value of a stone of more than one carat in weight is the product of the value of a one-carat stone by the square of the stone’s weight.

Cutting gemstones is called lapidary, and it is a skilled craft. There are several different ways of cutting and faceting gemstones in the period you are looking at, and the one used depends in part on the type of gemstone being cut. The price of a cut gemstone varies with demand (read fashion and economic purchasing power, as show in that article) and also the way the stone has been cut.

So to work out what a gemstone would cost you need to know both the weight, any flaws in the stone, and the cut. The article gives you an idea of the price of one-carat gemstones of various types at various times. To this you can then add the cost of cutting the stone (whoch will depend mostly on the time taken).

Then you need to add the cost of producing the necklace, and here again the price depends on the skill of the jeweller and the techniques used to make the piece(s). A highly decorative matched set of jewellery (which first becomes popular in the period you are looking at) with a fine finish will cost significantly more than a simple piece.

Finally, in reality, in the period you are looking at, no serious jeweller would have dreamt of mounting a gemstone in a pewter necklace. It wasn't - and isn't - done. At all. Things may be different in your setting, but at that point you need to think about why they would use pewter and not silver or gold.

 

[Finchbearer]

I agree with cup of joe in that we would really need a context - and of course if you’re making it all up and it’s a fantasy setting, then it’s kind of ‘anything goes’ but I think readers will generally lean towards something that is rooted in real world history or fact.

Pewter as far as I know is used for jewellery but it is the cheaper option, so I wouldn’t expect someone wearing pewter to be of a high social status, not at least in historical terms.

 

[CupofJoe]

I had a go using an AI to see what it could find.
ChatGPT came back with...

ChatGPT
The prices of gemstones in the 18th century varied widely depending on the type of gemstone, its quality, size, and origin, as well as market demand at the time. However, unlike today, there wasn't a standardized market for gemstones, so prices could fluctuate significantly.

Factors Influencing Prices:
Type of Gemstone: Some gemstones, like diamonds, emeralds, sapphires, and rubies, were highly prized and expensive. Others, like garnets or amethysts, were more affordable.

Quality: The color, clarity, and cut of a gemstone played a significant role in determining its price. Stones with vibrant color, high clarity, and a good cut were much more expensive.

Origin: The source of the gemstone could also affect its price. For example, diamonds from India were considered of higher quality, while sapphires from Sri Lanka (Ceylon) were highly valued.

Size: Larger stones were rarer and thus more expensive. The price increased exponentially with the size of the gemstone.

Market and Availability: The rarity and availability of certain gemstones also influenced their price. Some stones were more readily available and thus less expensive, while others were rare and commanded higher prices.

Examples of Prices:
Diamonds: In the 18th century, diamonds were extremely expensive. A high-quality diamond could cost hundreds or even thousands of pounds, a significant amount given the value of money at that time.

Emeralds: These were also highly prized and expensive. The best-quality emeralds from Colombia could fetch prices similar to diamonds.

Rubies and Sapphires: Both were highly valued, with prices depending on color and clarity. Burmese rubies were particularly sought after.

Amethysts: Before large deposits were discovered in Brazil in the 19th century, amethysts were considered precious and could be quite expensive.

Garnets: These were more common and thus less expensive, though still valued as a semi-precious stone.

Specific Price Examples:
Adam Smith's "Wealth of Nations" (1776) mentions that a diamond of a specific weight (carat) might cost around £15 to £20, which was a substantial sum at the time.
Emeralds and rubies could range from £10 to several hundred pounds depending on their size and quality.
Adjusting for Inflation:
For context, a pound in the 18th century would be worth several hundred pounds today. For example, £100 in 1770 is roughly equivalent to about £15,000–£20,000 today. Therefore, a gemstone priced at £100 in the 18th century would have been accessible only to the wealthy.

Conclusion:
In the 18th century, gemstones were luxury items accessible primarily to the aristocracy and wealthy merchants. Prices were high, particularly for high-quality stones, and the market was influenced by factors that are still relevant today, such as type, quality, and size.

 

[pmmg]

Its not really possible to answer this broad of a question. Gems are not an apples to apples comparison by themselves (rubies and diamonds are not the same), and the value of gems is typically based on an artificial belief of their value, which changes rapidly. Which is more valuable to a man dying of thirst? a diamond the size of his fist or a canteen full of water?


It would be better to say, what was the price of rubies over time, or diamonds, and not the broader, gemstones. But even in an apples to apples comparison (rubies to rubies), its still not really that either. Rubies in a culture where they are easily found would not be as valuable as another where they are imported. And some precious stones make up for the value of others that others don't have. Diamonds are all thought extremely valuable because of legends like the hope diamond, but diamonds themselves are actually fairly common.

In any setting, I think you are free to decide if a stone is worth 1000's of gold, or just a few silvers.

Since you are talking pewter, I would think the stones are not very valuable, cause pewter is too soft to put expensive stones in and think you will not lose the stones when the pewter's prongs break. If they are not high value stones, then I would put their cost on the low end of the scale. A few silvers, maybe a little more for being set in a necklace or ring. No one would put the hope diamond in pewter.


A great scene I loved from Atlas Shrugged, is when the character Jim Reardon makes a bracelet out of the stronger blue steel he invented, and gave it to his wife who was used to, and measured things, by an upper class standard. To her, it was a junky piece of steel chain that she discarded immediately. To him, it was the result of 30 years of his life's work, and developed at a cost of millions of dollars. The chain was more valuable than diamonds...but not in the wrong company.