Today is Old Rock Day. Did you know that? If you are a geologist you might have known. Old Rock Day is an opportunity to enjoy and appreciate old rocks and fossils. Perhaps you can start a rock collection. You can go out on a field trip in search of old fossils (the rock kind). Or, if you choose, you can polish them or add them to the window sill where you keep your house plants. You can pick them up in a river and let them dry out, make them into a fence so you will have good neighbors, or climb them and study their striations.
According to http://www.holidayinsights.com/ there are a lot of fun-filled, yet ill-defined, wild and wacky holidays. This is one of them. There is little information available on what this day was truly meant to mean. So, the interpretation and the means of celebration is left up to you.
By definition, fossils are old rocks. Jewelry stones are old rocks. And, coal is an old rock, too. You can celebrate any or all of these old rocks today.
Photo by Sanjay Acharya [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)%5D, from Wikimedia Commons