The 63rd edition of the Feninjer fair in São Paulo, Brazil, takes place Aug. 1–4.   (Above) Butterfly earrings in 18k gold with rubellites and diamonds; $2,698; Paixão Joias, Lagoa Santa, Brazil; 55-31-3689-0092; paixaojoias.com.br     (Inset) Rings in 18k rose gold with black rhodium, amethysts, and brown diamonds; $2,700 (both); Vancox, Belo Horizonte, Brazil; 55-31-3225-0650; vancox.com.br   Ring in 18k gold with black rhodium, white topaz, and citrine; $2,179; Guilherme Duque, São Paulo; 55-11-3068-8008; guilhermeduque.com     Baobab Bubbles bracelet in 18k gold with London blue, pink, and blue sky topaz, diamonds, and rubies; $3,021; Brumani, Philadelphia; 610-642-3512; brumani@brumani.com   Earrings in 18k gold with pink tourmalines and diamonds; $8,190; Vianna, Miami; 88