Gemologist and Color Stone Enthusiast
Put a handful of garnets on the table. Bring a strong magnet close.
And watch.
Some sit there looking thoroughly unimpressed.
Some twitch.
And some start following the magnet like you’ve suddenly taught gemstones to heel.
The first time you see it, it feels a little like magic. It isn’t. It’s chemistry. Which, frankly, is better.
Because the interesting question isn’t: Why is garnet magnetic?
The interesting question is: What did that stone just tell me?
There Is No Such Thing as “Just Garnet”
We do this in the jewelry trade all the time. We take something wonderfully complicated and give it a tidy little name. Ruby. Sapphire. Garnet. Done.
Except nature doesn’t work that way…
Garnet is a group of related minerals, not one mineral with one fixed recipe. Pyrope, almandine, spessartine, grossular, andradite and others all live under that big garnet umbrella.
And natural garnets are mixtures.
They don’t politely form themselves as chemically perfect textbook examples. So two reddish stones sitting beside one another can both quite legitimately be called garnet while having very different proportions of iron, manganese, magnesium, calcium and other elements in their chemistry.
They can look related. They can even look nearly identical. But internally? Different animals.
And that’s where the magnet gets interesting…
The label says garnet. The magnet asks another question.
Colour is seductive.
I say that as someone who has built a career around shiny rocks.
We look at a stone and our brain immediately starts sorting.
Red.
Orange-red.
Purple-red.
Dark red.
And before long we’ve begun constructing a story around what we think we’re looking at.
Sometimes we’re right. Sometimes the stone is quietly making a fool of us. Because chemistry does not only reveal itself through color. Iron and manganese, in particular, can make garnets paramagnetic. That doesn’t mean you’re dealing with a tiny refrigerator magnet. The stone doesn’t stay magnetized. But introduce a strong enough magnetic field and those elements within the garnet interact with it.
And the stone moves.
Think about how wonderfully strange that is. You are holding a crystal that formed somewhere in the earth, potentially hundreds of millions of years ago. You can’t see the iron. You can’t see the manganese. You cannot eyeball the proportions of its chemistry.
Then you bring a magnet close…and the stone answers.
That’s the bit I love.
A loupe tells me one thing. A refractometer tells me another. A spectroscope asks a different question again.
And a magnet?
A magnet is looking at the stone from an entirely different direction. That matters.
Because one of the easiest mistakes we make when examining gemstones is asking the same basic question five different ways and convincing ourselves we’ve collected five independent pieces of evidence. The useful tests are often the ones that interrogate a completely different property.
Magnetic susceptibility does exactly that. You can simply observe attraction.
Or, if you want to disappear rather deeply down the rabbit hole, that response can actually be measured and compared with other gemological properties to learn considerably more about the chemistry of a garnet.
Now we’re no longer doing a party trick. We’re interrogating the stone.
And that changes how I use this.
Put one beautiful garnet in front of me with all afternoon to examine it and I can happily become a gemologist. Put fifty stones from an estate on the table and tell me I need to make a buying decision?
Now I need to think differently.
I don’t necessarily need twenty-seven perfect identifications in the first ten minutes. I need structure:
Because the oddball is often where the interesting thing is hiding.
Imagine a parcel of reddish stones. Some are darker. Some are slightly more orange. A few have old labels. A few have labels written by someone whose confidence greatly exceeded their gemological ability. And half have no information whatsoever.
Bring in the magnet.
Most respond similarly. One responds strongly. Another barely moves.
Now I’m interested.
Not because the magnet has identified them. It hasn’t. But five seconds ago I had one pile. Now I have questions. And questions are valuable.
This is one of the habits I’ve developed from buying thousands upon thousands of stones. I’m constantly looking for the thing that breaks the pattern. If nineteen stones behave one way and number twenty behaves differently, number twenty gets my attention.
I don’t know yet. That’s important…. I don’t know yet.
Good gemology is often simply becoming comfortable with that sentence.
But now I know which stone deserves the next test. That is enormously useful.
This is where people get themselves into trouble.
You learn a clever test and suddenly everything becomes:
Strong magnetism = this.
Weak magnetism = that.
No.
Nature is considerably messier than the laminated charts we wish she would obey. Garnets are mixtures. Their compositions overlap. Their properties overlap. And a single observation almost never deserves to become a conclusion by itself.
The magnet gives me evidence. It gives me another coordinate. It does not give me the whole map. And that’s perfectly fine. I don’t need every test to identify the stone. I need every test to leave me knowing more than I knew before I performed it.
The trick isn’t making garnets chase a magnet across your desk. Anybody can learn that. The trick is knowing what to do with the observation.
That is how I think at the buying table.
Not: What single clever trick identifies this stone?
But: What is the fastest path from what I think I know to what I actually know?
That is a very different way of looking at gemology.
And it’s a big part of what I’ll be talking about at American Gem Society Conclave this September in Secret Teachings of a Gem Buyer.
📆Sep 15 @02:30pm 📍Olympic A
We’ll play with some very simple observations. Some slightly less obvious ones. And a few things that can turn a pile of unidentified stones into a much more interesting conversation rather quickly. Because the goal isn’t knowing every answer immediately.
The goal is knowing which question to ask next.
And sometimes…the stone moves.
