Paper Title:
Crystallography of Natural and Synthetic Gold Alloy Microstructures

To improve our understanding of the mechanisms of gold deposition, a comparison was made of the microstructures of a natural gold sample with a synthetic gold foil of similar alloy composition (approximately Au 90%, Ag 10%). The aim was to identify any similarities between the samples that could help increase our knowledge of how the natural gold microstructures formed and were modified post-mineralisation. The samples were analysed using electron backscatter diffraction to map their microstructure, with the synthetic gold foil then heated to and mapped at 400°C, 500°C, 600°C and 700°C. Both the natural and synthetic sample exhibited a dominance of ∑3 twin boundaries, but these were much less abundant in the synthetic sample prior to heating. The natural sample is dominated by coarse grains exhibiting lattice distortion and low angle grain boundaries, which more closely resemble the synthetic gold foil microstructure after recrystallisation has taken place, than the initial microstructure, implying that the grains have had time to grow. Performing experiments such as these allows direct comparison of gold microstructures where the formation conditions are known and the controlling mechanisms can be determined. This will improve our understanding of the important mechanisms behind gold deposition.

Chapter 7: Related Phenomena
Edited by
Matthew Barnett
A. Halfpenny, R. Hough, M. Nugus, "Crystallography of Natural and Synthetic Gold Alloy Microstructures", Materials Science Forum, Vol. 753, pp. 477-480, 2013
Online since
March 2013
Authors: Hideo Watanabe, Masayoshi Fuji, Atsuko Tada, Minoru Takahashi
Abstract:Nobel metal particles with nanometer size have attracted keen interest because of, for example, their high catalytic activity to be applied...
Authors: Peng Wang, Lin Hua Zhu
Chapter 4: Industrial Catalysis
Abstract:A new type of gold catalysts have been prepared by supporting gold colloids on layered double hydroxide (MgAl-LDHs) carrier at different pH...
Authors: Jin Wei Yu
Chapter 2: Surface Engineering/Coatings
Abstract:Electroless palladium are introduced to ENEPIG surface coating technology, from reaction principle to prevent oxidation of nickel-plated, but...
Authors: Chun Rong Wang, Xian Zai Yan, Li Li Yu
Chapter 11: Micro/Nano Materials and Preparation Technology
Abstract:The effect of the pH of the preparing solution on the size and shape of gold nanoparticles was studied in the solution containing soybean...
Authors: Yan Shan Huo, Lin Hua Zhu, Yan Lin Sun
Chapter 1: Environmental Chemistry, Chemical Manufacturing, Technologies and Engineering
Abstract:Au nanoparticles supported on MgAl-LDHs has been synthesized by coprecipitation method, gold colloid routs as well as intercalation and...