Laser Welding in Jewelry: How a Beam of Light Joins Gold

How does laser welding work in jewelry? A jeweler focuses short pulses of infrared light onto a tiny spot, so the gold melts and fuses in a fraction of a second while the metal around it stays relatively cool. For readers in Los Angeles curious about how fine jewelry is repaired and made today, it is one of the clearest examples of new technology working alongside traditional craft.

What is a laser, in one paragraph?

Laser stands for light amplification by stimulated emission of radiation. Inside a laser, atoms are pumped with energy until many of them sit in an excited state. When one releases a photon, it triggers others to release identical photons, all with the same wavelength and moving in step. Mirrors bounce that light back and forth until a powerful, narrow beam escapes. The very first working laser, built in 1960, used a ruby crystal, a story we told in The First Laser Was a Ruby.

Which lasers do jewelers use?

The classic jewelry welder is a pulsed Nd:YAG laser, a crystal of yttrium aluminum garnet doped with neodymium. It emits infrared light at a wavelength of 1064 nanometers, invisible to the eye. Equipment makers such as Han's Laser and Elettrolaser list Nd:YAG pulse welders specifically for jewelry spot welding and repair. The jeweler looks through a microscope with crosshairs, holds the piece inside a shielded chamber and fires one pulse at a time with a foot pedal.

Why does a focused pulse matter?

Two things make laser welding special: focus and time. The beam is focused to a spot well under a millimeter across, and each pulse lasts only milliseconds. Energy goes into a very small volume of metal, which melts, flows and solidifies almost instantly.

Because the pulse is so short, heat has little time to spread. Engineers describe this with the heat affected zone, the region around a weld whose structure is changed by heating. With a torch, that zone can include the whole piece. With a laser, it can be limited to a small area around the weld.

Think of a piece like the Bezel Set Diamond Tennis Bracelet, where each natural diamond sits in its own gold frame. Precise, local heat is exactly what you want when working on small joints in metal that surrounds stones.

Welding vs soldering: what is the difference?

• Soldering joins two pieces with a filler alloy, called solder, that melts at a lower temperature than the metal being joined. The jeweler heats the area with a torch until the solder flows into the seam.
• Welding melts the parent metal itself, sometimes with a little added wire of the same alloy, so the pieces fuse into one.

Both are real goldsmithing. Soldering is centuries old and still essential for many joins. Laser welding adds a way to work very close to a seam that a flame would affect more broadly.

Why is gold harder to laser weld than steel?

Gold reflects infrared light extremely well. That is the same property that makes gold coatings so useful on space telescope mirrors, as we explained in Why NASA Uses Gold in Space. A highly reflective metal bounces much of the laser energy away instead of absorbing it. Gold also conducts heat very well, so the heat it does absorb moves away from the spot quickly.

The result is that jewelers adjust the power, pulse length and spot size for each alloy. Yellow, rose and white golds behave a little differently because their alloy metals differ, which you can read about in our guide to gold alloy chemistry.

What can lasers do, and what can they not?

Lasers are well suited to small, precise jobs: closing a link, building up a worn area with fine wire, fixing a seam near a stone, joining tiny components during making. They are less suited to large joins or to replacing the judgment of a skilled hand.

Heat is still heat. Some gems and organic materials, such as pearls, opals and emeralds, are sensitive, and every jeweler weighs the risk before working near them. The laser is a tool, not a guarantee.

New technology, old hands

I love moments like this, when physics walks into the workshop. A ruby crystal led to the laser, and the laser now helps goldsmiths do work that once took a steady torch and a lot of luck. But the design, the proportions, the texture of a raw surface and the final polish still come from a person who knows the metal.

The Raw Diamond Ring is a good example of that balance: an organic gold shape with raw texture, unpolished on purpose, holding a natural diamond. The pavé on the Wavy Bow Diamond Hoops is another place where small, careful metalwork meets stones. Margaret Krinetz Fine Jewelry, handmade in Tel Aviv and shipped to Los Angeles, makes every piece to order.

Frequently asked questions

Is a laser weld as strong as a soldered joint?
A well made laser weld fuses the metal itself, so it can be very strong. A good soldered joint is also strong. The right choice depends on the piece and the join.

Can laser welding be done near diamonds?
Diamonds tolerate heat better than many gems, and the laser's local heat helps, but jewelers still assess every stone and setting before working.

How long does delivery to Los Angeles take?
Every piece is made to order in 4 to 6 weeks, then shipped by DHL Express in 3 to 5 business days. Shipping is free on orders over $1,500.

Which part of jewelry science should we explain next? Write to me with your question, I love these conversations.