The document discusses rare and valuable gold coins and ingots as a form of wealth, including: - The 1849 US $20 Liberty Gold Piece and 1907 US Indian Head $20 Gold Pattern as the two most valuable gold coins in the world, worth over $20 million and $15 million respectively. - An 1852 Adelaide Assay Office ingot and coins from the same year among Australia's rarest, including a £5 piece worth $950,000 and £1 piece worth $700,000. - Other valuable Australian coins such as an 1887S Victoria Jubilee coin set worth $1 million and an 1893S Victoria pattern half-sovereign worth $170,000.