Thoriated glass convex lens from a vintage Kodak camera
Size: 21mm in diameter and about 9mm thick.
Kindly observe that the item pictures display slightly discernible tool marks on this item.
Thoriated glass lenses may contain up to 30% thorium by weight.
If the lens has developed a brown tint over time, the discoloration can be mitigated by exposing the lens to ultraviolet light.
Thoriated glass is a glass material used in the manufacture of optical systems, specifically photographic lenses. It is useful for this process due to its high refractive index. Thoriated glass is radioactive due to the inclusion of thorium dioxide, the oxide of the radioactive element thorium. It has therefore been succeeded as a material of choice for the glass including lanthanum oxide. Thoriated glass can contain up to 30% by weight of thorium. The thoriated glass elements in lenses over time develop a brown tint reducing transmission and interfering with neutral color reproduction.
This listing meets the requirements of NRC 10 CFR 40.22
It also meets U.S.P.S domestic shipping requirements for exempt limited quantities of class 7 materials according to –347.22 “are eligible under 49 CFR to be shipped as excepted packages for limited quantities” and –Exhibit 347.22 Activity Limits– and also –173.435– Table of A1 and A2 values
Geiger counter is not included