During the 17th century, Europeans yearned for gold and silver metals, pearls, emeralds and other treasures that were heavily mined in Central and South America. The excavations and study of the Buen Jesús y Nuestra Señora del Rosario (also known as the "Tortugas") shipwreck from the 1622 Tierra Firme fleet has produced a diversity of artifacts reflecting Spanish colonial trade with the Americas towards the end of Spain’s golden age, early in the reign of King Philip IV.
The "Tortugas" shipwreck site yielded twenty-seven gold bars in varying states of completeness, with distinctive markings impressed on the surface. A semi-circular line and dot stamp confirmed payment of the 20% royal quinto tax (the Spanish "royal fifth" tax, i.e. the tax levied by the Spanish crown on mineral products) while the purity of the gold was a marked in Roman numerals (such as XXI for 21 karat purity) set in rectangular frames; above appeared solid dots enclosed by smaller rectangular frames denoting fractional values (one dot for one-quarter karat, two dots for a half, etc.).
Other markings on the bars represent the stamp of the New World foundries where the bars originated. The word ‘EN RADA’ appears with several co-joined letters (P and L, A and E, and R and A and N). Other stamps read ‘SARGOSA PECARTA’ and ‘SEBATN ESPANOL’. These stamps represent abbreviated names of the foundries of the Colombia mines where this colonial gold was extracted and cast. The ‘SARGOSA PECARTA’ gold bars derived from Zaragoza, which started operations in 1582, while ‘SEBATN ESPANOL’ signifies extraction at the seemingly small San Sebastian mines of Timaná. The ‘EN RADA’ gold is an abbreviation of ‘Peñarenda’, a wealthy family that owned gold mine concessions in various parts of the New World, including seemingly Colombia and Mexico.
Cobs are the original “treasure coins”, struck and trimmed by hand from 1500s through 1700s at Spanish mints. Crude but impressively decorated, nearly all cobs include a cross as the central feature on one side and either a coat-of-arms (shield) or tic-tac-toe-like “pillars and waves” on the other side. Silver cobs are known as “reales” and gold cobs as “escudos”. Some cobs were struck with a date, and most show a mint mark and an assayer’s initial or monogram, the mint official who was responsible for weight and fineness. Size and shape were immaterial, so that most cobs are far from round or uniform in thickness. Cobs were generally accepted as good currency all around the world. Pirates famously referred to them as “pieces of eight” (8 reales) and “doubloons” (any gold cobs, but originally 2 escudos.) The piece of eight was the immediate forerunner of the American dollar worth 8 reales. The $ symbol started life as the Spanish coin symbol for the Pillars of Hercules (two pillars with banners wrapped around them), the gateway to Spain on country’s coat of arms.
The assemblage of 1,184 silver cob coins in various degrees of degradation found at the "Tortugas" wreck site contains no coins dated later than 1622. Authentic replicas of the "Tortugas" cobs have been crafted into sterling silver and 14K gold jewelry.
While the heyday of pearl exploitation had long ceased by 1622, the Venezuelan oyster beds were still visited in hope and with some success in the first quarter of the 17th century. Pearls were the earliest source of wealth imported by colonial Spain from the Americas.
A total of 6,838 pearls scattered across the site were recovered from the "Tortugas" wreck through the use of the project’s SeRF sieve system. When recovered from the dredged sediments, many of the pearls were a dark gun-metal gray color, but after conservation reverted to a range of colors and lustrous finishes. The shapes of the pearls include round, pear, egg, drop, button, baroque and blister as defined by the Gemological Institute of America, and vary in color from white to cream, rose, pink, silver, yellow, blue and black. Some 636 of the pearls are drilled with holes, likely intended for use as beads perhaps strung or possibly sewn onto clothing. From a sample of 6,494 well-preserved pearls, the sizes range from 1-10mm.