24 karat vs 18 karat gold: which to buy?
Differences in purity, durability and price between 999 and 750 gold for investment and jewelry.
At a glanceThe decision between 24-karat gold (999.9 fine pure gold) and 18-karat gold (750 alloyed jewelry gold) is one of the most critical considerations when purchasing bullion or fine jewelry in Switzerland. While 24k gold offers unmatched metallurgical purity and tax-exempt safe-haven status, 18k gold is the definitive benchmark of Swiss haute horlogerie and fine jewelry, engineered specifically to endure daily mechanical wear. This guide explores their metallurgical properties, hardness, valuation per gram, and Swiss legal classifications.
Comparative Matrix: 24 Karat (999‰) vs 18 Karat (750‰)
| Evaluation Metric | 24 Karat Fine Gold (999‰) | 18 Karat Jewelry Gold (750‰) |
|---|---|---|
| Fine Gold Content (Purity) | 99.99% pure gold (999.9‰) | 75.0% pure gold + 25.0% alloy metals |
| Alloy Additives | None (100% pure elemental Au) | Copper (rose gold), silver (yellow gold), palladium (white gold) |
| Vickers Hardness (HV) | 25 to 40 HV (Extremely soft and ductile) | 125 to 185 HV (3 to 5 times harder and more durable!) |
| Specific Gravity / Density | 19.32 g/cm³ | 15.20 to 15.60 g/cm³ depending on alloy tint |
| Resistance to Dents & Scratches | Very low (deforms under direct hand pressure) | High (safely grips precious diamond prongs) |
| Natural Color & Tone | Rich, deep warm orange-yellow | Versatile: Swiss 2N/3N yellow, 4N/5N rose, rhodium white |
| Swiss VAT Treatment (LTVA) | 0% VAT (Investment gold exempt under Art. 18) | 8.1% Swiss VAT applies to new jewelry retail |
| Primary Application | Bullion bars, bank cast ingots, sovereign coins | Wedding bands, solitaire rings, luxury watches, chains |
Why 24-Karat Gold Is Impractical for Daily Jewelry
Pure elemental gold is exceptionally malleable. A 24k gold ring worn during ordinary daily activities bends and deforms against hard surfaces such as steering wheels or door handles. Most crucially, the delicate prongs holding a valuable diamond setting in 24k gold bend open under minimal shock, resulting in lost gemstones. To solve this, Swiss master goldsmiths alloy pure gold with 25% copper and silver, creating a rigid crystalline structure that locks diamonds in place for generations.
Scrap Value and Swiss Buyback Pricing
The intrinsic financial value of gold scrap is directly determined by its fine gold content:
- 1 gram of raw 24k gold: Equals 100% of the live LBMA spot price (e.g., CHF 84.00/g).
- 1 gram of raw 18k gold: Equals exactly 75% of spot: CHF 84.00 × 0.750 = CHF 63.00/g.
When selling scrap jewelry at Swiss counters, refiners deduct a standard 8% to 12% melting margin to cover XRF assaying, induction melting, and acid parting refining costs.
Frequently Asked Questions (FAQ): 24k vs 18k Gold
Can you wear 24k gold jewelry occasionally?
Yes, in Asian cultures ('Chuk Kam'), 24k gold is traditionally given as wedding dowry and stored in vaults, but it is rarely worn during rigorous daily routines.
Why does Switzerland favor 18k over 14k or 9k?
Swiss federal hallmarking and luxury watchmaking hold 18k (750‰) as the historical minimum of true prestige, whereas 9k (375‰) contains more base alloy than noble precious metal.
Buy Investment Gold in Switzerland (VAT-Exempt)
Buy and store physical gold in secure Zurich or Geneva vaults at direct live LBMA spot rates.