UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
How it Works
Ask a Question
Search Topics
Our Scientists
Science Links
Contact Information
We were doing an experiment with vinegar and some fossils. We poured the vinegar on the fossils and they fizzed. In about an hour we saw whitish crystals, some were slightly rusty colored. We wondered what this was and what caused it.
Question Date: 2007-03-24
Answer 1:

What are you doing wrecking fossils?

Carbonates fizz when exposed to acid, and bicarbonates especially fizz. The acid liberates the carbonate ion, which then dissociates into carbon dioxide and water.The water remains liquid, but the carbon dioxide turns into gas.

The crystals are residue left behind. The red is probably hematite (rust). I don't know what the white is, likely quartz (silicon dioxide).

Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2020 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use