Buying better: notes from the market.
We buy and sell jewelry every day, and most of the questions we get are the same ones. These three guides cover the categories we handle most — lab-grown diamonds, jadeite and silver — in plain language, without the sales pitch.
General information only. It is not a grading report or an appraisal; for a specific stone, ask for a certificate from a recognised laboratory.
Lab-grown diamonds, without the sales pitch
A lab-grown diamond is a diamond. It is carbon crystallised in the same structure as a natural stone — the difference is where it grew: in a reactor in weeks, rather than in the earth over billions of years.
What is actually different
Chemically, optically and physically, nothing that matters to the eye. A gemologist cannot tell them apart without an instrument that reads trace nitrogen or growth patterns. What differs is origin, and what follows from origin: rarity, resale value and price.
Why the price fell so far
Production scaled up quickly, and wholesale prices for lab-grown stones have dropped dramatically since 2020. That is good news if you want a large, clean stone for a setting. It is bad news if you expect the stone to hold value — lab-grown diamonds are a purchase, not an investment. Buy them because you like the stone and the price, not because you plan to resell.
How the stones are made
- HPHT — high pressure, high temperature. Mimics the conditions underground; often used for smaller stones and for colour treatment.
- CVD — chemical vapour deposition. Diamond grows layer by layer on a seed plate; common for larger stones.
Both methods produce real diamonds. The method matters less than the finished grade, and whether any post-growth treatment was used to improve colour — which should be disclosed on the certificate.
What to check before you buy
- Certificate. IGI and GIA are the reports you will see most often for lab-grown; NGTC is common in China. The report number should match the laser inscription on the girdle.
- The four Cs, but weighted differently. Cut matters most for how the stone looks; colour and clarity can be slightly lower than you would accept in a natural stone, because you are paying far less per carat.
- Price per carat. Compare quotes per carat, not per piece — settings vary enormously and can hide a weak stone price.
- Setting budget. A large lab-grown stone still needs a proper setting. Do not spend the whole budget on the stone and then set it in a flimsy mount.
Jadeite, explained: A, B, C and the four words that matter
“Jade” in English covers two different stones: jadeite (翡翠) and nephrite (软玉). They look similar to a beginner and are priced very differently. When people talk about expensive green jade, they almost always mean jadeite.
A, B and C
- A-grade (A货) — natural jadeite, not bleached, not impregnated, not dyed. Colour and texture are as the stone formed.
- B-grade — bleached to remove impurities, then filled with polymer to improve transparency. Looks better than it is, and deteriorates over time.
- C-grade — dyed. Colour sits in the cracks and fades.
- B+C — both treatments. The most common trap in cheap markets.
A-grade commands a real premium, and the price gap between A and B+C is enormous. A certificate from a recognised laboratory (NGTC, GTC and similar) is the baseline, not a nice extra.
The four words: 种、水、色、工
- 种 (texture) — how fine and dense the crystal structure is. Glassy, ice-like, glutinous and bean-like are the usual shorthand, from finest to coarsest.
- 水 (water) — transparency. A stone with good “water” lets light through and looks alive.
- 色 (colour) — judged on intensity, brightness, hue and evenness. Bright, saturated, even green is the benchmark; grey or yellowish tones reduce value.
- 工 (craft) — the cut and polish. A good cabochon is domed evenly, symmetric and free of visible flaws at the surface.
How to avoid the usual mistakes
- Be suspicious of “bargains”. A vivid, transparent jadeite bangle at a low price is almost always treated.
- Look at the stone in daylight, not only under the shop’s warm lamps.
- Ask what treatment, if any, has been applied — and get it in writing.
- For bangles and carved pieces, check for cracks with a torch; a hairline crack can become a break.
Silver 101: 925, 999 and how to keep it bright
Silver is the most affordable of the precious metals and the easiest to get wrong — mostly because two very different alloys are sold under the same word.
925 vs 999
- 925 (sterling silver) — 92.5% silver, 7.5% copper or other metals. Harder, holds shape, takes settings and clasps well. Most jewelry is 925.
- 999 (fine silver) — 99.9% silver. Softer, more prone to bending and scratching; used for bangles, chains and objects rather than stone-set pieces.
Both are real silver. “925” is not a downgrade — it is the practical choice for anything that has to hold a stone or survive daily wear.
Plating and colour
Much silver jewelry is rhodium-plated (white) or gold-plated to improve colour and slow tarnishing. Plating wears with friction — rings and bracelets first — and re-plating is normal maintenance, not a defect.
Why silver tarnishes
Tarnish is silver reacting with sulphur compounds in the air, not a sign of fake metal. Sterling tarnishes faster than fine silver because of the alloy. Humidity, swimming pools, hot springs and some cosmetics accelerate it.
Keeping it bright
- Wear it — gentle friction on skin actually slows tarnish.
- Store dry, ideally in a sealed bag with an anti-tarnish strip.
- Wipe with a soft polishing cloth after wearing; avoid abrasive pastes on plated pieces.
- Take it off before swimming, bathing or cleaning with chemicals.