Sebright: Glauconite


The final colour of my pallet that was still eluding me had been green. My only consolation in this frustration is that it has been is shared by every artist going back hundreds of years. There just aren’t many naturally green pigment sources out there. Historically, an artist’s choice boiled down to either malachite (which is a copper, and I knew wasn’t going to be within the 100 mile limit) and terra verde – green earth.

To begin my search I contacted Pam Sangster, the Regional Resident Geologist for Southern Ontario. She was very helpful in answering my questions and generously devolved a secret location where she had found a mineral called glauconite which, in the pigment world, is called green earth. The photo above is hers and that thin crust of greenish crystals on the limestone is the glauconite.

The mineral glauconite is one of those that is widespread, and most places have a little bit around, but in Ontario it is fairly rare. Traces of it can be found in Gull River Formation limestone. Pam’s find was a wonderful addition to this project and quite unexpected.

Green earth is best described as being grayish-green in colour. Historically, its use as a pigment goes far back into history; for example, it is one of the colours identified in a pigment set from a shop at Pompeii. While a green mineral, such as glauconite, is aways present in the pigment, ultimately this clayish pigment is a real hodgepodge of materials, and so every location presents a different variety of the colour. This has led to some types of green earth being named locally. A famous example of this would be Verona Green (which is green earth from just outside Verona).

Pam made an introduction for me to the owner, Mr. Eid Attia, and in a follow-up conversation with him he invited me up to Attia Quarry to scout around and see what could be found.

With the arrangements made, Reiner, Maggie and I headed up to the other side of Orillia to visit the Attia Quarry in Rama Township. Eid Attia, the owner, had mentioned that we would need to go to the new quarry if we hoped to find some of the, “green stuff” but we had arranged to meet at the Stone Cottage Industries location where the quarried stone is stored for sale. I have to say that we were all impressed with the limestone present (Reiner said he had never seen such tight limestone). Driving along we saw 4′ x 8′ sheets of solid stone only 6″ thick! If ever I am looking to build with stone, this is where I’ll come.

Eid had arranged everything for us and the pit manager was ready to help. It was only afterwards that I came to realize that they were understaffed that day and that our tour was probably an extra thing they could have done without. The pit manager gave us directions to the Sebright pit location and promised to follow shortly.

Standing outside the gate we gazed at the guard cows present at the pit’s entrance (this was Reiner’s joke). Once inside I followed the manager’s truck in my little VW Golf as far as I could, but soon we had to abandon the car and climb into his truck’s bed as the ground became rougher. Eid had mentioned that his quarry was situated on 600 acres of land, and about half way to the small dig site I became really thankful for the guided tour – without it we never would have found the right location.

Even when the truck stopped I wasn’t sure initially what I was seeing as the clearing ahead was covered in green growth from our vantage. But once we stood upon the hill, an opening about 15 feet wide was clearly visible (as you can see in the photograph at the top). We started looking for some nice green glauconite crystals (like the ones in Pam’s photograph) but we didn’t have any luck finding them. In later conversation with Eid, he said that the next time I was up that way he would show me where I could collect such little green gems. But, at that point, without any sign of glauconite and such a large property around us, I began to wonder if we were going to find any green at all and if our long drive had been in vain.

But, although we couldn’t locate the pure glauconite crystals, we did find green in the end. At the bottom of the rough limestone pile, where the water had been running down the exposed rocks, we found a one inch thick coating of green mud. Carefully using my rock hammer I carved out a section to take back to my studio. While very happy to be collecting this green pigment, once this was done we quickly retreated back to the regular quarry as the mosquitoes and deer flies were out in force!

This is an exciting colour to add to my project and I’m dubbing it, “Sebright Green”. My next task will be see whether I can remove some of the impurities (such as limestone particles) from the pigment and hopefully create a denser colour.


While the green earth I collected from Sebright was a nice colour once ground, I have been curious what effect a couple of different experiments might have upon it. What you see in the above photograph is the two extremes I ended up with. The colour of the pigment when ground up originally is roughly in the middle of these two.

On the left is the green I created by putting the green earth into an acid, removing all the limestone impurities. It is a very cool green and I like this colour a lot.

On the right is the green I created by decanting the pigment after mixing it in water and then counting to ten (which allowed some heavy foreign matter to settle). This colour I am really pleased with. It is a warm green and very alive. It is also almost exactly the same shade as the Cyprus green earth I have in my pigment collection.

I always find it interesting when a raw pigment source is refined a bit. Sometimes it has little effect, but, as in this case, sometimes it proves to be the final tweak a colour needs to be really spectacular!

1 thought on “Sebright: Glauconite”

  1. Wow! That’s a very pretty green but there’s such a tiny amount. I hope you can find enough of it to be useful. By the way – I read the article on you in the Kitchener Waterloo Record last weekend. What a great introduction to your project!


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