Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.
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| Tumbaga Bar Lot 194 in the current Sedwick Auctionl See link below. |
Here is part of the lengthy lot description.
Large tumbaga gold ingot, 1816 grams, marked with fineness V and three dots (5.75 karat, or 23.96% fine), also marked with R and S and several tax stamps of Charles V, Holy Roman Emperor, ex-"Tumbaga wreck" (ca. 1528), Garcia-Barneche Plate. Approx. 12-1/2" x 2" x 1". This the largest and arguably most significant of the very few GOLD ingots found on the "Tumbaga wreck," which is the only known source of such ingots, all of which are very low in fineness (marked between 5-3/4 and 8 karats). Of the thirteen pieces known, all but two are cut down in their time, the intact two being a long and skinny rod and the present lot, which is somewhat club-shaped with a wide diameter and one end bulbous, the rounded bottom showing small marks of fineness V (incuse) and three dots in a column immediately followed by an S-shaped mark in a box plus a single dot in a box, the flat top of the bar showing four partial tax stamps (which show parts of CAROLVS IMPERATOR) and one mark with an R in a box (formerly seen as a B)...
XRF analysis on this piece reports it as about 39% gold, 56% copper and 5% silver, a fineness (9.32K) that exceeds what is marked on the bar itself (5.75K) by over 60%! Curiously, the exposed metal in the "bite" at the end shows more of a gold color, leading us to speculate that the surface was purposefully tinted to pass off a fraudulently low assay. In any case, this bar and its shipmates are true tumbaga in that they were made from native artifacts created from a mix of copper and gold...
And here is the link.
https://auction.sedwickcoins.com/Large-tumbaga-gold-ingot-1816-grams-marked-with-fineness-V-and-three-dots-5-75-karat-or-23-96-f_i33011507
The bar is just a touch over 64 ounces, and has a current bid of $37,500, with an estimate of up to $70,000.
Tumbaga is relevant to some of the other posts I've done this year.
I've only found one tumbaga item.
Tumbaga is a word used by the conquistadors to describe the copper and gold alloys used by the pre-Columbian natives. It varies widely in composition and often contains other metals. The natives would use acid to accomplish depletion gilding so the surface of the item would be a more pure gold than the rest of the item.
I've described the depletion gilding process before.
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I did an experiment the other day that I tried to catch with my video camera, but the glare off the water was too bright and I didn't get it, so I made a drawing. It is rough.
I colored some small washers in bright colors and place them on the beach where the water would reach them. At first the water only got some of them, and washed those into the water. Eventually they all got washed into the shallow water.
The waves were probably more towards the north than shown in my drawing, but they were not directly north. They had a definite slant to the left.
Anyhow, I followed the colored washers down into the shallow water and along the shoreline until they seemed to come to a resting place. I could see them for a while, but had to use my detector to find them a good part of the time.
If the waves and currents changed, I'm suspect they would have been moved some more.
That seems to be what happens with coins on the beach. There were several places I used to metal detect in South Florida where people would congregate on the beach, but I would consistently find a good collection of coins and things n the shallow water to the south.
I'm disappointed that I wasn't able to show a video of exactly how the waves moved the objects. It took a while anyhow.
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Miss Costa, a Great White shark of over 1600 pounds, was recently detected off the Florida Panhandle.
https://www.foxnews.com/science/great-white-shark-florida-panhandle-researchers-say
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The surf is only one or two feet, but we are having some nice high tides and negative tides now.
Happy hunting,
TreasureGuide@comcast.net
