How do I bench test iolite pleochroism on drilled beads?
Work under neutral daylight by a window or a daylight balanced lamp and use a white card. Lay the strand flat. Pick a bead, then rotate it around its drill and also flip its faces. Watch for a shift from violet blue to gray blue, and some views may even read yellowish.
Mark the darkest blue-violet view with a wax pencil dot near the hole. Test a handful of beads across the strand. If most read blue from the same viewing side, that strand will string up saturated. Iolite's strong pleochroism is the reason this works, and we prize strands that read blue-violet face-on.
- Read with glasses off if needed to see body color rather than facet glare.
- Compare two beads side by side in the same orientation before deciding.
Which shapes show the deepest blue violet?
Shapes that present a broad face to the viewer tend to look darker in iolite. That is because the strong blue-violet direction shows best when you look into the face rather than along an edge. Top-drilled drops and face-flat cuts usually win.
See the drill notes on our shape pages for context: rondelles are center drilled along the short axis, pears are commonly top-drilled across the point, and marquise are often top-drilled across a point.
- Rondelles: good color if you align faces outward and limit rotation.
- Top-drilled pears: usually the strongest face-on color in necklaces.
- Top-drilled marquise: bold, dark reads in long earrings and fringe.
- Lengthwise-drilled marquise or drops tend to read lighter unless laid flat.
How should rondelles be strung to look darkest?
Rondelles are drilled through the center on the short axis, so the viewer sees alternating faces and rims as beads twist. After bench testing, flip each bead so the same face points outward and keep that orientation across the strand.
Use snug spacing to reduce spin. Knotting adds about 1 mm per knot, which helps hold orientation and can slightly deepen the look by reducing light leak between beads. Keep gray-leaning beads near the clasp or as spacers.
- Check the front and center before crimping, then spot check mid-strand.
- If a few beads refuse to read blue, set them aside for earrings.
What about pears and marquise, point-up or point-down?
For pears, prefer top-drilled across the point so drops hang point-down and present a full face. Rotate each bead on the wire before crimping to lock the blue-violet side forward. Center-drilled pears read more edge-on and often look lighter.
For marquise, choose top-drilled across a point for earrings and fringe, then set the face-forward orientation during assembly. Lengthwise-drilled marquise show more edge and can read cooler or gray unless you mount them flat to the viewer.
- Graduate sizes, but keep the same color-facing orientation.
- Place any yellow-leaning beads toward the back row or ends.
How many 6 mm beads do you need?
Plan your count so you can cull and still finish the piece. For a 7.5 in bracelet with a clasp, the beaded run is about 6 in, which is about 25 beads of 6 mm. A 16 in choker takes about 61 of 6 mm, and an 18 in necklace about 70.
A 15 to 16 inch strand of 6 mm rondelles has about 65 to 70 beads. Standard Jaipur strands run 13 to 16 inches, so one strand often covers a bracelet or choker, and two strands make a longer necklace. Knotting will add length and reduce the bead count slightly.
How do we check a Jaipur-cut strand before we buy?
We look for consistent face-on blue across the front of the strand. In an oval or drop, one face often looks inky and the side washed out, good Jaipur cutting and drilling aim the blue face forward. We aim to stock strands where most beads read blue from the front, as noted in our iolite stone guide.
Ask us for daylight photos or a short video, or see us at an InterGem show on our schedule. Anish here: at the table, I fan the strand, rotate a few beads in the center, then decide quickly. If most read blue-violet face-on, it usually strings up rich.