Starfish 80 Faceting Diagram: Precision Gem Cutting Design by Marco Voltolini
The Starfish 80 is a highly captivating 5-fold mirror-image symmetry faceting diagram created by master gem design artist Marco Voltolini. Specially calibrated for an 80-index gear, this design showcases a distinct star-like pattern that maximizes brilliance and scintillation across medium-to-high Refractive Index (RI) gem species.
1. Design Overview & Suitable Gem Materials
Optimized for a baseline Refractive Index of 1.540, Starfish 80 is extraordinarily versatile. While it performs exceptionally well on Quartz family minerals (such as Smoky Quartz, Amethyst, and Citrine), it delivers brilliant light return when cut on higher RI gem materials including Topaz, Tourmaline, Beryl, Spinel, Sapphire, and Garnet.
The 5-fold pentagonal outline paired with carefully stepped crown facets gives finished gemstones a unique star effect, making it an excellent choice for custom designer jewelry and collector gems.
2. Technical Design Specifications
- Design Name: Starfish 80
- Designer: Marco Voltolini
- Required Index Gear: 80 Index Gear
- Optimized Refractive Index (RI): 1.540 (Quartz & higher)
- Facet Count: 56 Facets + 10 Girdle Facets = 66 Total Facets
- Symmetry Type: 5-fold, mirror-image symmetry
- Length-to-Width (L/W): 1.000
- Table-to-Width (T/W): 0.527
- Pavilion Depth Ratio (P/W): 0.412
- Crown Height Ratio (C/W): 0.162
- Volume Ratio (Vol./W³): 0.202
3. Cutting Instructions & Angle Sequence
PAVILION CUTTING SEQUENCE
| Facet | Angle | Index Settings (80 Index) | Instruction |
|---|---|---|---|
| 1 | 42.36° | 02-14-18-30-34-46-50-62-66-78 | Cut to centerpoint |
| 2 | 90.00° | 02-14-18-30-34-46-50-62-66-78 | Set stone size |
| 3 | 41.00° | 80-16-32-48-64 | Meet girdle |
CROWN CUTTING SEQUENCE
| Facet | Angle | Index Settings (80 Index) | Instruction |
|---|---|---|---|
| A | 51.13° | 02-14-18-30-34-46-50-62-66-78 | Set girdle thickness |
| B | 42.00° | 80-16-32-48-64 | Meet girdle |
| C | 35.55° | 08-24-40-56-72 | Meet girdle |
| D | 26.62° | 04-12-20-28-36-44-52-60-68-76 | Meet A, B, C |
| E | 14.54° | 80-16-32-48-64 | Meet B, D |
| F | 19.95° | 08-24-40-56-72 | Meet C, D |
| G | 0.00° | Table | Meet F, E |
4. Practical Lapidary & Cutting Tips
- Preforming: Pay close attention when setting up the initial 90° girdle preform (Step 2). Maintaining accurate 5-fold pentagonal proportions is key to getting clean meetpoints across the crown.
- Crown Meets: When cutting Facet D (26.62°), ensure it meets precisely at the intersection of A, B, and C to create the clean star shape.
- Polishing: Work sequentially from pavilion centerpoint to girdle, and polishing the table last (Facet G) at 0° angle.
Explore more precision faceting diagrams, custom gem designs, and lapidary guides on Horizon Gems!
0 Comments