Numbers Mumbo Jumbo - what do all of those numbers mean? - post 268  July 17 2026

Part 3 of a series on Metals. 

 

             #5773 Portuguese earrings 19.25k gold  

 

Today I was surprised to read a question from someone who claimed to be a qualified jewelry appraiser.  He asked the question 'what does 925 silver mean?'. I thought that after a few years in the antiques business, words like 925 and 'sterling' should become encoded in your DNA. I was wrong.

Let's go back to last week, when we discussed mixing precious metals with other metals for various reasons. The result is called an 'alloy'. The amount of other metal in the mix varies. Add more copper to lower your costs, to make a pinker color or most importantly, to strengthen the alloy. 

We want to know how many parts of the whole are precious metal and how many are lesser metal. 
The amount of each metal compared to the whole can be expressed in percentages - for example 75% gold and 25% other metals; 92.5% silver and 7.5% other metals; 95% platinum and 5% other.
  
Being humans and coming from different backgrounds and cultures, we might express the ratio in different ways. We might say how many parts in a thousand are gold and how many copper? We might say how many parts out of a whole 24 are gold and how many copper? They all give us the same information - the ratio of metals to each other, but they express it in different ways. The example of percentages above expressed parts in 100. 

With some very basic arithmetic skills, we can easily convert 75% to 750 parts in a thousand or 18 parts out of 24. It all means the same thing. 
Similarly, 56% is another way of talking about 14 parts of 24. 
Easy Peasy. 

So now we know how to express the purity of precious metals. 

#7662 low k gold and silver Masonic orb 

So why do you care? Well, you are going to expect to pay more if you buy candlesticks of 925 parts silver than if you buy candlesticks with a lot more nickel hidden in them. You expect the price of 14k earrings to be less than 18k earrings. You want to know that what looks like silver (or gold) is in fact what you are paying for and will behave in the expected way as the years go by.

#5533 14k cross

Many countries had norms and standards of what was expected in the ratio of fine metals in alloys. (that useful word). 
In France for example, gold was expected to be at least 18 parts of a total of 24. In Britain, 14 parts was allowed and in the USA there were no mandatory rules. 
In India, where they really, really love gold, the norm was 22 parts of 24 and in Portugal 19.25. 
Silver was usually 925 parts of a thousand in Britain, but for a short while, they increased the number to 950.
This ratio is the most basic of what we generically call 'hallmarks' and we will delve into them Next Week.  

        #7678 18k bangle.  

Questions and comments: Please email antiques@brendaginsberg.com
Find jewelry on www.brendaginsberg.com
------------------------