The Tri-City Gem and Mineral Society was back again Wednesday afternoon for another installment of Science Rocks! at the Harker Heights Public Library, this time with a demonstration on growing salt formations.
Ruth Rolston, president emeritus for the organization and who now serves as publicity chairman, was on hand to lead the hourlong demonstration and tutorial for the 30 children and 10 adults who came for the event.
She was uniquely qualified for the day’s lesson—as she told her audience, she wrote a research paper about salt, and also collects it.
Rolston began by giving everyone some interesting facts about salt: “Did you know that salt is important to make your body work?” “Salt was so valuable once, the Romans were paid in salt — that’s where we get the word ‘salary.’ This is where we get the term, ‘worth his salt.’”
She also showed them some examples of halite, the mineral form of rock salt, which varied in color from pink, to purple, to green.
The children had a lot of questions, which Rolston answered with a touch of humor and a lot of sincerity. Seven-year-old Michael Tate asked her how many kinds of salt there are; her answer was, “I collect salt, and I have 107 types.”
They looked skeptical, until she started showing them some of the different types she brought with her, including pink Himalayan salt.
Once Q & A was over, it was on to the demonstration. Rolston first showed her audience the materials they would be using: a glass jar; hot, distilled water; salt (Rolston used Morton’s); small sticks; string; and red food coloring (“Red, for the Harker Heights Knights,” Amanda Hairston, children’s librarian, reminded the kids).
Then Rolston began adding the salt to very hot distilled water, explaining that she was making a “super-saturated solution,” which she then defined for the audience of both kids and parents.
“This is where you put more into the solution than the solution will hold,” she explained, then demonstrated.
“Put the salt in, and keep stirring until you see the salt on the bottom,” she said. “When it starts to settle on the bottom, it means it’s getting super-saturated.”
She added the food coloring to the solution, and the jars will filled. Finally, strings were tied to sticks, to be left dangling into the solution once everyone took theirs home.
“Leave it to grow,” Rolston told everyone. “You will start to see it within hours.”
In between steps, she was still giving everyone facts about salt. Salt is a rock; it is the only rock you can eat; and there is a salt mine in Canton (albeit defunct).
All the children, and even some parents, got to take home their own salt formations, and everyone walked away with a new appreciation for salt.
“This is what we (the Society) are supposed to do, is educate,” Rolston said.
The Tri-City Gem and Mineral Society will be at the Gem and Mineral Show at the Frank W. Mayborn Civic and Convention Center in Temple on Oct. 13-14.
Admission is $5 for adults, and children 12 and under are admitted free if accompanied by a parent.