Most Recent Program Information
May 2024 Program
-Tom Tucker, a long-time member, demonstrated a few tricks to identify unknowns and gave some sage advice. He has a degree in chemistry and was/is a geologist.He said that years ago, pyrite could be easily found in Dumfries Creek. The area is now a National Park, so no collecting there. (He noted that a lot of locations where collecting was once allowed are now parks, shopping malls, or private. Not helpful for us rockhounds!)
He demonstrated a chemical test for copper by placing a few grams of CuSO4 in a jar (from ZEP root control agent) and adding ammonia hydroxide. The solution turned blue, indicating copper.
While living in MT for 15 years or so as a geologist and as a tourist businessman, he traveled a lot. He once traveled from Casper Wy to Yellowstone, and found a huge pile of whitish material. This apparently was a pile of tailings from the Pratt sodium mine.The material was probably (Na3H(CO3)2 · 2H2O) trona, or natrum. This chemical was mined and carried off by the train-car load. Tom had grown some natrum crystals to show us. He used pool Clorox from Wal-mart and mixed this chemical with water. The clear fragile crystals absorb water easily and there was water pooling in the bottom of the bowls.
Tom demonstrated using drops of 10% HCl on calcite and limestone. Bubbles and vapor appeared readily. (A good test to show whether a specimen is limestone or dolomite - dolomite will not fizz.) Concentrated white vinegar will work, but not as well.
He brought some pieces of porcelain from an old commode that can be used as a streak test plate for us to take.
He mentioned that a good place to collect geodes is near Hamilton, IL at the Jacob mine. The keokuk geodes collected there contain either quartz or calcite. The charge is by the bucket-full. These geodes can also be found near Keokuk, Iowa. Keokuk geodes are some of the most beautiful in the world, and people travel from all over to collect them.
THANK YOU, TOM, FOR YOUR INTERESTING DEMONSTRATIONS!