GemDuo Siam Ruby is a diamond-shaped bead with two parallel holes going through the length of a bead. 

Designing with GemDuo Beads:

GemDuo beads have a gently beveled top with a raised ridge in the center. These beads are very similar to DiamondDuos and can be used in many patterns that call for DiamondDuos. Use GemDuo Beads with other Czech glass beads to create attractive patterns and designs.

GemDuo specifications:

• Color: Siam Ruby
• Category: 2-Hole Bead
• Shape: GemDuo, diamond
• Country: Czech Republic 
• Material: Lead-Free Glass
• Measurements: 8x5mm
• Hole size: 0.8mm, fits up to 24 gauge wire or thread
• Quantity: Each tube contains about 8.5 grams of beads (approx. 60 pieces).