"Alpaca Mexico 925" Silver Jewelry: The Stamp Does Not Mean Sterling

No. Jewelry stamped "Alpaca Mexico" or "Alpaca Mexico 925" is NOT 925 sterling silver.

What Is Alpaca?

• Alloy composition: Copper (55–65%), Nickel (18–22%), Zinc (17–22%) — sometimes trace lead, tin, iron
• No silver content — despite "925" stamp (misleading / fraudulent)
• Also called: Nickel silver, German silver, Argentan, New silver, Paktong
• Appearance: Silvery-white, tarnishes to gray-green, harder than sterling

Why the "925" Stamp?

• Misleading marketing — exploits consumer association of "925" = sterling
• Not regulated in Mexico for non-precious alloys
• Tourist/souvenir market target

Real Sterling Silver Marks in Mexico

• .925 or 925 (alone or with maker's mark)
• Sterling
• Plata (Spanish for silver) + .925
• Taxco (famous silver town) + .925 + maker's mark
• Hecho en México + .925 + registered mark (e.g., T-123)

How to Test

1. Magnet: Alpaca is magnetic (nickel/iron); sterling is not
2. Acid test: Sterling turns creamy red; alpaca turns green/blue
3. Weight: Sterling denser (10.37 g/cm³) vs. alpaca (8.7 g/cm³)
4. Tarnish: Sterling = black sulfide; alpaca = green copper corrosion
5. XRF: Professional elemental analysis

Value Difference

• Sterling (.925): ~$0.70–$0.90/gram (silver spot ~$0.75/g) + craftsmanship
• Alpaca: ~$0.02–$0.05/gram (base metal) — costume jewelry price

Buy from reputable Mexican silver dealers (Taxco, Guadalajara, Mexico City) with proper hallmarks. "Alpaca Mexico 925" = costume jewelry, not investment silver.