Image Credit

Description:

MicroBiology Science Project Looks alone aren't enough to tell which of these pieces of jewelry are gold and which are merely gold-plated, or other metals altogether. From left to right, these pieces are made up of other metal alloys, gold plating, and 24-kt gold.

Source:

www.life.umd.edu

License:

Permission granted via e-mail by photographer Dr. Rollins.

Source URL:

http://www.life.umd.edu/classroom/bsci424/LabMaterialsMethods/AntibioticDisk.htm