^Lot 61 Silver "tumbaga" bar M-19, 5.25 lb av (2381 grams), with markings of fineness 9CCCCLXX (970/2400), s

Silver "tumbaga" bar M-19, 5.25 lb av (2381 grams), with markings of fineness 9CCCCLXX (970/2400), serial RC, assayer B~Vo, and two partial tax stamps, ex-"Tumbaga Wreck" (ca. 1528). 7" x 3" x ¾". Typical "half-brick," neatly formed with smooth bottom and sides but somewhat rippled top from the cooling of the metal, with assayer's "bite" in one corner and all markings on bottom consisting of two tax stamps left of center and the rest in a cluster to the right, the left side of the fineness likely missing the number for one thousand (iU), as the bar does not appear to be only 40% silver (970/2400) and probably should be marked iU9CCCCLXX (1970/2400) for 82% silver. In fact, XRF testing inside cracks does show a fineness of about 83% silver, while surface readings of about 93% probably reflect the typical loss of non-silver alloy from conservation. From the "Tumbaga Wreck" (ca. 1528), with Sedwick photo-certificate and autographed copy of Agustín García-Barneche's The "Tumbaga" Saga (2nd edition, 2018).