I expected to find more on this topic on the world wide spiderweb, but since few have posted pics of this phenomenon I thought it would be good to do so. Maybe carpenters who work with cedar see it all the time but it was interesting to me.
In a nutshell, my wife asked if I would cut some some disks from a large red cedar branch that broke off a nearby tree. I used a miter saw (we call it a chop saw ’round these parts) to cut a bunch of disks –about 3″ diameter, 1/4″ thick drink coasters basically.
The cedar aroma was great and we left one wafer sitting around on the pantry shelf. A couple of days later I was back in the pantry searching for some type of food item that would require zero forethought or preparation time, and glancing at the cedar disk I noticed a frosty, sparkly something on its surface.
Looking closely, the red heartwood center of the wooden disk had grown very fine crystalline whiskers, some around 1 to 3mm long (yes I’ll switch to metric on you like that when the micron range becomes ponderable). The little clear needles seem to orient in various directions and extend out from the surface at different angles.
My quick and dirty “solubility test” consisted of a drop of water in one area and a drop of rubbing alcohol in another. The crystals were unaffected by the water and dissolved nearly instantly in the 70% isopropyl alcohol. Oh, and the flame from a lighter vaporizes them pretty instantly also.
From what I can find, the substance is likely crystallized libocedrol, a component of the aromatic oils found in the tree. The tree is Juniperus virginiana and I don’t know if any particular conditions like temperature, moisture content, etc. affect the crystal formation or if the tree just had a lot of the compound available to release. Nor have I researched what other trees may have it or if it’s common to see. I do know the internet needed a few more pictures of it so here are a few from my little USB microscope.