During July, 2018 the Walker Mineralogical Club went on a field trip to Dog Lake, near Battersea, north of Kingston, OntarioThe goal was to find the spot where well-formed, light-green crystals of diopside occur in a coarse-grained calcitic marble. Sometimes the diopside crystals can ger fairly large, perhaps up to 60mm or so. I had visited the site 25 or so years ago with Mike Irwin and was happy to go back to try and improve on what I found way back when. I was a little hazy on exactly where it was but we did manage to find our way, through fields and dense deciduous woods to the spot. Here are a few pictures and text to give you a flavour of what it was like.
Through the Woods
This is the terrain that we hiked through to get to the Dog Lake Diopside Occurrence; deciduous forest with a floor carpet of trilliums and poison ivy. There wasn't poison ivy right where we were collecting but close by there was lots.
Daniel Joyce at Work
Some of us started on the outcrop right at the shoreline. There were spots where the calcite had been worn away to expose the crystals of diopside and no soil covering the outcrop. Daniel was taking advantage of that exposure. Look at that physique! (Just like his Dad USED to have.)
Here, Matthew is working through a zone where the calcite had been naturally etched away by slightly acidic groundwater to release diopside crystals into the soil. Matthew also found some small apatite crystals in a different area of the occurrence.
Andrew, our fearless field trip leader, decided to dig straight down into a weathered zone and managed to come up with some nice crystals, naturally etched out of the calcite.
Here is a nice crystal that Andrew recovered from his hole. Almost textbook!
Bruce and Uli had a hold going in the underbrush. I'm not sure what they found. They look happy anyway!
Dale likes to break rock andhe is good at it. He found a likely looking spot and was chiselling off chunks of diopside-containing marble to more carefully break up at home. He also intended to dissolve calcite with acid to expose crystals.
This was an interesting beach just 25m or so from where we were collecting. The granules of the beach are not sand, as we normally see beaches. The beach is composed of 3-5mm coarse granules of calcite and diopside, similar to what we were collecting, mostly calcite. It was a very hot day and a great place to skinny dip. (Sorry no pictures of that! 🙂 )
Here is a sharp diopside crystal that Daniel Joyce found. Nice faces!
A nice cluster of diopside crystals, 6.0cm across, naturally weathered out of calcite matrix.
Diopside Crystals in Marble
These diopside crystals are naturally exposed on the surface of calcite rich marble. (That is, as opposed to exposed by acid etching)
Another nice cluster of diopside crystals,naturally etched out of calcite.