Round Lab Grown Ruby Gemstone – Medium (3.5–7.5mm)

Round Lab-Grown Ruby Gemstones for Custom Jewelry

Bring rich red color to your next jewelry design with a round lab-grown ruby. Whether you are planning a July birthstone ring, a pendant or a pair of earrings, choose the diameter that suits your setting and the look you want to create.

Choose Your Size

This listing features round lab-grown rubies from 3.5 mm to 7.5 mm. Each Size/Carat option pairs the stone’s diameter with its estimated carat weight, making it easier to compare sizes before choosing.

• Gemstone: Lab-grown ruby
• Shape: Round
• Color: Red
• Diameter range: 3.5–7.5 mm
• Uses: Custom rings, earrings, pendants and July birthstone jewelry

Size and Carat Guide

• 3.5 mm: approximately 0.22 ct
• 4.0 mm: approximately 0.33 ct
• 4.5 mm: approximately 0.46 ct
• 5.0 mm: approximately 0.62 ct
• 5.5 mm: approximately 0.82 ct
• 6.0 mm: approximately 1.05 ct
• 6.5 mm: approximately 1.32 ct
• 7.0 mm: approximately 1.55 ct
• 7.5 mm: approximately 1.85 ct

Carat weights are estimates. Use the diameter in millimetres when choosing a stone for an existing setting, and confirm the fit with your jeweller.