The subject of precious stones in the glacial drift is brought before the public from time to time by the report of gems being found accidentally either in or upon the drift. Most of the gems are diamonds and occasionally are of considerable size and value. No diamonds have been reported from the drift of Iowa. Several of good quality have been reported from Wisconsin while others have been found in Michigan, Ohio and Indiana.
Proceedings of the Iowa Academy of Science
©1914 Iowa Academy of Science, Inc.
Muilenburg, Garrett A.
"On the Occurence of Precious Stones in the Drift,"
Proceedings of the Iowa Academy of Science, 21(1), 203-204.
Available at: https://scholarworks.uni.edu/pias/vol21/iss1/29