Saxony was ruled by two cousins in 1544: John Frederick I (Elector of Saxony) and his cousin Maurice (Duke of Saxony). Both rulers’ names appear on each side of the quarter thalers produced in this year. They were enemies involved in religious wars, although they were both Protestants. Two types of quarter thalers from 1544 occur: a pierced random find from Transylvania (Romania) with four shields on the reverse, heavily worn, and another one with three shields on the obverse side, found in the Głogów Hoard (Poland), which is well preserved. Why did they issue two types in the same year? Was it a matter of silver title or other historical factors? Nondestructive investigation methods were used: XRD revealed the phases within the alloy and patina layer; SEM-EDS revealed the morphological aspects and their elemental compositions, which were correlated with XRF results. The results show that both coins have closer silver amounts, from 91 to 96 wt.%. The EDS results were in good agreement with the XRF results. Lead traces indicated a difference between them: the four-shielded coin is lead-free, while the three-shielded coin has a moderate amount of lead, about 0.5 wt.%. The archeological data evidence that the four-shielded coin issued in 1544 is rarer than the three-shielded one because it was issued during specific historical conditions. Black patina is formed by a mixture rich in copper oxides mixed with silver oxides and Ag₂S. The presence of silver sulfide in the patina layer confirms that the pierced coin was in prolonged contact with the skin surface. Also, the finest traces of minerals embedded in the patina layer (e.g., quartz, kaolinite, and calcite) suggest that they were embedded in the patina via prolonged exposure to particulate matter. The mineral inclusions in the patina would have been more numerous if they were formed underground. Thus, the pierced four-shielded coin was probably worn as jewelry by nomads, while the three-shielded coin was most likely treasured in a well-preserved hoard.

At the beginning of the reign of Louis I of Anjou, King of Hungary (1342–1382), various types of currency were introduced, undergoing repeated devaluations until 1360. According to Lajos Huszár, denarii of the Saint Ladislas type were issued in 1358–1371, with a fineness of approximately 0.93, whereas Saracen Head denarii were assigned to 1373–1382 and described as being of lower fineness. Recently, Csaba Tóth claimed that the Saracen’s Head Denarii were issued in the middle of the reign of Louis I, and the last types of denarii were those with the representation of Saint Ladislas. A recent archeological find from Transylvania (Romania) contains 3 intact Saracen Head denarii and 12 fragments and only 3 fragments of Saint Ladislas denarii. The significant number of fragments facilitates advanced microstructural investigations of the bulk alloy, including XRD correlated with SEM microscopy and EDS elemental spectroscopy. It results in a silver content of about 89.15 ± 0.93 wt.% for Saracen Head denarii, while Saint Ladislas ones have a significantly decreased fineness of 81.75 ± 2.54 wt.%. These values support the newest chronology discussed in the literature, placing the Saracen Head denarii in the middle of Louis I of Anjou reign, while the Saint Ladislas type belongs to the latest part of the reign. Patina layers were investigated regarding the resting ground, which contains quartz, clays (kaolinite and muscovite mixture), and calcite. Thus, the oxidized layer formed directly on the metallic surface is dominated by copper oxides, which further interact with the calcium carbonate from the soil generating a green layer of malachite. This layered corrosion extracts copper from the outermost layers, causing significant silver enrichment of the coin’s surface of about 97 wt.%, which affect nondestructive investigations. The slight micro-incision of the fragment’s sides enabled accurate measurement of the silver fineness despite the presence of corrosion features. Such an approach could be applied for evaluation of other coins’ fineness performing the micro-abrasion on their edges, allowing for SEM-EDS measurements while preserving the visual integrity of coins.