Late 18th c Portuguese Beryl Cluster Ring

A c. 1780s Portuguese cluster ring, in all original form and set with 29 green beryls / greenish aquamarines weighing approx. 2.73 ctw. The rose gold setting is entirely original and unmodified, featuring a concave posterior formed to accommodate the finger’s natural curvature, and a trifucated fleur-de-lys shank popular with Portuguese rings made during this period. The workmanship and contour details of the present example parallel the shank and shoulder design of a c. 1783 Portuguese ring in the Koch Collection (see n. 1057, Rings: The Alice and Louis Koch Collection by Anna Beatriz Chadour), as well as another illustrated on p. 210 of A Joalharia em Portugal 1750-1825 by Gonçalo de Vasconcelos e Sousa. All three rings feature petal-like trifucated shoulders with the larger triangular centerpiece ‘folded’ at the tip and narrower beveled side ‘petals’. In terms of form, the present ring belongs to a group of oval cluster rings in the Lisbon National Museum of Ancient Art (see p. 78, Five Centuries of Jewelry by Leonor d’Orey). These rings, while large per late 18th c fashion, are appropriately proportional to the finger and comfortable to wear (unlike some dimensionally awkward later conversions from brooches and components). The cluster design with a central gem surrounded by concentric halos was prevalent throughout Europe during the second half of the 18th century. However, Portuguese examples are particularly charming due to the trapezoidal scissor cut gems, which enable a neat caliber arrangement of the stones.The gold beading accents are representative of Portuguese jewelry made during the last quarter of the 18th c.; while this design feature was also popular throughout Europe during this period, the Portuguese versions feature smaller beading and greater use of interspersed layering within a piece.

The present ring’s gems test as beryl, the mineral species encompassing color varieties such as emerald and aquamarine (much like how ruby and sapphire are color varieties of the mineral species corundum). Depending on the time of day and quality/source of light, the ring’s gems appear light mint green, chrysoberyl-like, pale dusty blue, or a delicate seafoam color. Color variety assignation can be difficult due to variation between the individual gems: the central stone has a notable blue undertone and can be characterized as a pale aquamarine, while some of the surrounding halo stones are closer to green beryls (when intensely green, a beryl is characterized as emerald; lighter green varieties are known as green beryl). The gems originate from Minas Gerais, Brazil, which since c. 1729 has supplied Portuguese jewelers with various color varieties of quartz, beryl, chrysoberyl, tourmaline, and topaz. The region is the world’s most important source of gem-bearing pegmatites, associated with granite that make up the cores of mountains, and including hydrothermal veins carrying minerals (e.g. beryllium, boron, fluorine etc) from the surrounding environment to deposit them in fissures and cavities to form gem crystals. The famous mines of Brazil and Colombia—including Muzo, Chivor, and Ouro Preto/Minas Gerais—were created this way.
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