There are three things a jewelry buyer needs to understand before spending money on anything described as gold. The differences between them are not marketing. They are chemistry. And they determine whether the piece purchased today will still exist in five years, or ten, or fifty.
The three categories are solid gold, gold-filled, and gold-plated. A fourth term, vermeil, sits inside this conversation and is worth clarifying.
This is the complete guide.
Solid gold
Solid gold means the piece is made of gold throughout. Not as a coating. Not as a layer. Gold, as a metal, mixed with other metals to give it strength.
Pure gold, known as 24 karat or 24k, is generally too soft for jewelry meant to be worn every day. Depending on the design measurements, the piece could bend, scratch, and warp. For this reason, fine jewelry is almost always made from gold alloys. The karat number tells you the percentage of pure gold in the alloy.
- 24k: 99.9% gold. For most designs: too soft for daily wear.
- 22k: 91.6% gold. Traditional in South Asia and the Southwest Asia.
- 18k: 75% gold. European standard for fine jewelry.
- 14k: 58.3% gold. American standard for fine jewelry.
- 10k: 41.7% gold. US legal minimum to be sold as "gold."
The remaining percentage is other metals: copper, silver, palladium, zinc. These are what give gold its final color. Yellow gold, white gold, and rose gold are the same base gold, alloyed with different secondary metals.
Solid gold jewelry can be resized, repaired, melted down, and recycled indefinitely. It does not tarnish. It does not wear off. Cared for reasonably, a solid gold piece will last for centuries. This is why solid gold is the material of heirlooms.
Gold-filled
Gold-filled is often confused with solid gold and is nothing like it.
Gold-filled jewelry is made by mechanically bonding a layer of solid gold to a base metal, typically brass. Under United States Federal Trade Commission regulations, a piece marked "gold-filled" must contain at least 1/20 (5%) gold by weight, and the gold layer must be at least 10k quality, though 12k and 14k are more common.
The gold layer on a gold-filled piece is roughly 100 times thicker than on gold-plated jewelry. This makes it far more durable than plated pieces. A well-cared-for gold-filled piece can last ten to thirty years before the gold layer begins to wear through in high-friction areas such as the inside of a ring shank or the clasp of a bracelet.
Gold-filled jewelry is a legitimate category. It is a reasonable choice for someone who wants the look and feel of gold without the price of solid, and who accepts that the piece will eventually wear through.
But it is not an investment. Gold-filled jewelry cannot be melted down for its gold content in any economically meaningful way. It cannot be resized the way solid gold can. It holds no resale value in the secondary market. When it wears out, it is discarded.
To answer the question directly: yes, gold-filled contains real gold. But most of the piece is not gold.
Gold-plated
Gold-plated jewelry is base metal, typically brass or copper, coated in a thin layer of gold through a process called electroplating. The gold layer is typically between 0.5 and 2.5 microns thick. For comparison, a single human hair is roughly 70 microns thick. The gold on most plated jewelry is thinner than a hair.
Because the layer is so thin, gold-plated jewelry wears through relatively quickly. Under normal daily wear, the gold layer begins to visibly wear off within two years, exposing the base metal underneath. This is why plated jewelry is typically priced the lowest in the market of gold-associated jewelry.
There is a place for gold-plated jewelry. Trend pieces. Fashion earrings for a single season. A statement piece for a specific occasion. This category is not to be criticized. It is to be understood.
There is also a variant called "heavy gold electroplate," which requires a plating of at least 2.5 microns and lasts somewhat longer. It is still fundamentally the same category.
Vermeil
Vermeil, pronounced ver-may, is a specific category of gold-plated jewelry that meets stricter standards. Under US FTC regulations, a piece can only be labeled vermeil if it meets three requirements:
- The base metal is sterling silver, not brass or copper,
- The gold layer is at least 2.5 microns thick, and
- The gold used is at least 10 karat.
Vermeil is a step above standard gold-plated jewelry because the sterling silver base holds value on its own, and the gold layer is thicker. A vermeil piece worn with care can last several years before the gold begins to wear off.
The four categories side by side
- Solid gold. Pure gold alloyed with other metals. Value throughout the entire piece. Lasts indefinitely. Fully recyclable. Retains meaningful resale value at close to metal weight.
- Gold-filled. Thick gold layer bonded to brass base. Contains meaningful gold (5% or more by weight). Lasts 10 to 30 years. Not economically recyclable. Minimal resale value.
- Vermeil. Thin-to-medium gold plating over a sterling silver base. Silver holds some value. Gold layer wears off in several years. Not recyclable as gold.
- Gold-plated. Very thin gold coating over brass, copper, or other materials. Gold wears off within 2 years.
The investment perspective
Here is what the four categories mean financially.
Solid gold jewelry is one of very few consumer purchases that retains a meaningful percentage of its value. The metal itself has been used as a store of wealth for five thousand years, and it continues to be held in reserve by central banks around the world. When you buy a solid gold piece, you are buying a portable, wearable, private form of the same asset that governments hold in vaults.
A solid gold piece purchased today for $1,000 will, at minimum, retain the value of the gold weight it contains. That value has historically appreciated across long time horizons and provided a hedge against currency instability. The design labor and craftsmanship on top of the metal is what accounts for the price above scrap value.
Gold-filled, vermeil, and gold-plated pieces do not do this. They contain gold, but not in a form or quantity that can be recovered. When they wear out, they become landfill.
This does not mean the plated categories are wrong. It means they are a different category of purchase entirely. They are fashion. Solid gold is finance.
The illi approach
The heart of illi is solid gold. Our fine jewelry is solid, alloyed, and enduring. Every diamond we set is lab-grown. Both choices are deliberate.
Solid gold is what allows a piece to function the way fine jewelry has functioned across cultures and across centuries. It can be worn every day. It can be resized when a hand changes shape. It can be repaired if damaged. It can be inherited. If necessary, it can be sold, in any city, in any economy, at close to its metal value.
We also make a small number of pieces in gold-plated sterling silver and gold-plated stainless steel. These serve a different purpose. Not every piece worn is meant to be an heirloom. Some are meant for a season, a specific occasion, a specific mood. Those pieces are made with the same design integrity as our solid gold pieces, and we are transparent about what they are and what they are not.