Antique/ Georgian or Victorian 18ct Gold Sapphire and Diamond Ring

1 Sapphire, 4.5 x 4.5mm, weight: 0.29ct
12 Diamonds, 1.8 x 1.8mm, weight each: 0.025, total weight: 0.30ct

Ring weight: 2.25 grams, length x width: 9.8 x 10mm, height: 5.3mm, size: P 1/2