The shipwreck site of the Central America contains four
types of gold: coins, assay ingots, individual nuggets that miners pulled
directly from the ground and streams, and - amazingly, gold dust strewn amid
the sediment. Each is characterized by the extraordinary variety and texture
and offers fascinating insight into the history of the fledgling and somewhat
haphazard economy of San Francisco and Sacramento during the gold rush era.
Dust and nuggets, which were among the most intriguing finds of the
expedition, were the rawest form of gold coming out of the streams and gold
fields in and around the foothills of the Sierra Nevada. Gold dust represented
the base of San Francisco's earliest monetary system. Sending dust and raw
nuggets all the way to the US governments main mint in Philadelphia for
assaying and coining was too costly and time consuming. Thus, San Francisco
relied on a "dust economy," in which the gold dust, measured by the weight or
by the "pinch," served as currency.
This was a poor medium of
exchange, however. For one thing, California gold dust varied from only 58
percent to more than 98 percent pure. Measurement was imprecise and prices
highly speculative. At one point, the glut of dust in old San Francisco was so
great that buyers were paying only $8.00 per ounce, far below the $20.67 US
government standard for pure gold and roughly $18.00 per ounce paid by the
Philadelphia Mint for gold dust.
Dust is collected when Nemo's sea-vac
is used to clean up a specific work site on the ocean floor. It is necessary to
sift through the sediment to extract the gold and small artifacts hidden
within. After finding the first gleaming fleck, Bob regularly panned for gold
dust. It is ironic that this gold is twice-mined, once from California streams
and again from 8,000 feet under the ocean surface in the 20th century.
The nuggets are the most diverse gold pieces recovered. They are natural
forms, like the dust, but intricate and far more unusual. Each one is unique
with the pieces ranging from just bigger than flecks of dust to fist-sized
specimens of gold, quartz, and other minerals. Because the wealthy first-cabin
passengers and the commercial shippers tended to carry their gold in ingots or
coins, many of the nuggets on the Central America were almost certainly the
prized possession of frugal miners traveling east in steerage class. For
example, the Hearn brothers from Missouri, who took turns guarding their
satchel of gold throughout the entire journey by steamship and train from San
Francisco, and Joseph Bassford, who dropped his own while leaping into a
lifeboat, are thought to have been carrying nuggets with them. Others who
reportedly abandoned their wealth in despair just prior to the sinking were
also in possession of gold in this form.