Tandon Gems

December birthstone gifts: tanzanite, zircon and turquoise by size

Tara Tandon, Tandon GemsPublished April 15, 2024· Reviewed September 5, 2026· 3 min read

This article is a reference guide. Some older product details and imagery have been omitted pending verification. Confirm the current strand, price and quantity with Anish before ordering.

Short answer

Pick turquoise 4 mm rondelles or heishi for bracelets. Keep tanzanite and natural zircon for necklaces and earrings in 3 to 4 mm rondelles or small drops. A 16 inch strand gives about 95 to 100 beads at 4 mm and 65 to 70 at 6 mm, enough for one choker or two bracelets. At 3 mm, expect about 133 beads per 16 inch strand.

In short

  • Tanzanite and zircon suit necklaces and earrings best
  • Turquoise bracelets work well in 4 mm rondelles or heishi
  • 4 mm strand, about 95 to 100 beads, one choker or two bracelets
  • 6 mm strand, about 65 to 70 beads, one choker or two bracelets
  • 3 mm strand, about 133 beads per 16 inch length

Which sizes should I use for bracelets, necklaces and earrings?

For bracelets, we recommend turquoise in 4 mm rondelles or heishi. Tanzanite and natural zircon belong in necklaces and earrings. For delicate necklaces and earrings, use 3 to 4 mm rondelles in tanzanite or zircon, and 4 to 6 mm rondelles or heishi in turquoise.

See our stone notes for color and care: tanzanite, natural zircon and turquoise. For shapes, rondelles are the workhorse and pears shine in earrings: rondelle, pear, heishi.

How many 4 mm beads do you need, and what can one strand make?

A 7.5 inch bracelet uses about 38 beads at 4 mm. An 18 inch necklace uses about 104 beads.

A 15 to 16 inch strand of 4 mm rondelles has about 95 to 100 beads, so plan on one choker or two bracelets from a single strand. For an 18 inch necklace, add a few spacers or use two strands if you want full bead coverage.

How many 6 mm beads do you need, and what can one strand make?

A 7.5 inch bracelet uses about 25 beads at 6 mm. A 16 inch choker uses about 61 beads. An 18 inch necklace uses about 70 beads.

A 15 to 16 inch strand of 6 mm rondelles has about 65 to 70 beads, which covers one choker or two bracelets. For an 18 inch necklace, one full 16 inch strand often suffices; add small spacers if your strand runs short.

Do 3 mm rondelles make sense for fine necklaces and earrings?

Yes, they sit light and drape beautifully in tanzanite and zircon. At 3 mm you get about 8.3 beads per inch and about 133 beads per 16 inch strand.

One 16 inch strand generally covers a 16 inch choker after you allow for a clasp. For an 18 inch necklace, add spacers or combine strands to reach the length you want.

What about 8 mm for bold necklaces or roomy stacks?

An 8 mm 15 to 16 inch strand holds about 48 to 52 beads. A 16 inch choker needs about 46 beads, so one strand works. An 18 inch necklace needs about 52 beads, which is right on the edge.

A 7.5 inch bracelet uses about 19 beads at 8 mm. Two bracelets come from one strand with some beads left for earrings. We favor 8 mm in turquoise; we skip it in tanzanite and zircon bracelets.

How should I string and finish for durability and length?

Allow about 1.5 inches for clasp and findings when you plan yields. Chokers use about 14.5 inches of beads, princess length uses about 16.5 inches.

Use flexible beading wire for turquoise bracelets and check fit before trimming. Keep tanzanite and zircon for necklaces or earrings with secure crimps or wrapped wire. Tara here, we turn a bead as we string tanzanite to enjoy its blue to violet shift without overhandling the strand.

Which stones go where, and why does it matter?

Tanzanite and zircon run 6 to 7.5 on the Mohs scale and can chip at facet edges, so we keep them off wrists. Turquoise does well in bracelets if you keep it away from oils and perfume.

Tradition places all three as December birthstones, a blue trio that pairs well with silver or gold. For earrings, pears, trilliants and small rondelles hang clean and light.

Common questions

Can one 16 inch 6 mm strand make an 18 inch necklace?

Often yes. An 18 inch necklace uses about 70 beads at 6 mm, and a 15 to 16 inch strand has about 65 to 70 beads. Add a few spacers if your strand is short.

How many bracelets can I get from a 16 inch 4 mm strand?

A 7.5 inch bracelet uses about 38 beads at 4 mm. A 15 to 16 inch strand holds about 95 to 100, so two bracelets are covered with extras for earrings or spacers.

Are 3 mm rondelles strong enough for bracelets?

We avoid bracelets in tanzanite and zircon at any size due to brittle edges. Use them in necklaces and earrings instead, where they shine.

What sizes of turquoise work for stackable bracelets?

Use 4 mm rondelles or heishi for a slim stack. For a chunkier look, 6 to 8 mm works, keeping wrist comfort and weight in mind.

Will knotting change my bead counts?

Yes. Knotting between beads adds about 1 mm per knot, lengthening the piece and reducing how many beads you need for the same finished length.

Sources and checks

  1. Bead and Necklace Size Charts - International Gem Society
  2. Chart - How many beads I need? - Jewelry Discussion - Ganoksin Orchid Jewelry Forum Community for Jewelers and Metalsmit
  3. Celebrating Blue with December Birthstones | December Birthstone Color

Catalog details are reference information. Ask Anish to confirm the current strand, price and availability.

Want a strand like the ones in this post?

Message Anish with the stone, shape and size you have in mind. Photos of actual strands on request.

Ask on WhatsApp

Keep reading