Title page for ETD etd-04262002-142814


Type of Document Master's Thesis
Author Dunkle, Stacie E.
URN etd-04262002-142814
Title Romarchite and Other Corrosion Phases on Metal Artifacts from the Queen Anne's Revenge (1718)
Degree Master of Science
Department Geological Sciences
Advisory Committee
Advisor Name Title
Craig, James R. Committee Chair
Lusardi, Wayne R. Committee Member
Rimstidt, james Donald Committee Member
Keywords
  • corrosion
  • abhurite
  • pewter
  • tin
  • metal artifacts
  • Queen Anne's Revenge
  • romarchite
Date of Defense 2002-04-19
Availability unrestricted
Abstract
Metal artifacts from the pirate Blackbeard’s flagship, Queen Anne’s Revenge (1718), were studied and a preliminary assessment of the corrosion products that have formed on them is presented. Artifacts made of iron, lead, tin, copper, mercury, gold, and silver were recovered from the site with only those made of precious metals displaying no corrosion products. Detailed analysis was conducted of the surfaces of pewter artifacts, made from a tin-rich alloy, revealing corrosion products composed of romarchite (SnO), hydroromarchite (5SnO.2H2O), and abhurite (Sn3O(OH)2Cl2). For comparison, corroded pewter artifacts originating from five other archaeological sites submerged in seawater, dating to between ~1550 and 1733, were analyzed. All of these samples also exhibit abhurite, romarchite, and hydroromarchite, however, some of the artifacts also display cassiterite (SnO2). Textural analysis indicates that abhurite is the first alteration product to arise, followed by romarchite and hydroromarchite and, in some cases, ending with the formation of cassiterite. The absence of cassiterite on many samples demonstrates that, while appearing to be stable under the conditions that were present, the phase has not yet had time to form. Because of the very limited stability field for romarchite, its presence on these artifacts seems to be the result of a kinetic effect, while its universal appearance suggests that it is a required step in the oxidation of pure tin to the final most stable phase of cassiterite. Knowledge of the stability of pewter corrosion products and their effectiveness as agents of passivation can provide insight into the processes of tin corrosion.
Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Thesis.PDF 2.25 Mb 00:10:26 00:05:22 00:04:41 00:02:20 00:00:12

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.