The 1970 Double Obverse Penny: An Expert Authentication Guide

The 1970 Double Obverse Penny: Your Ultimate Authentication Guide

In the shadowy world of rare coins, few prizes spark as much collector adrenaline as the 1970 double obverse penny. With clever fakes flooding the market, knowing how to spot the genuine article isn’t just smart collecting – it’s guardianship of numismatic history. As someone who’s handled more error coins than I’ve had hot teas, let’s explore together the telltale signs that separate museum-worthy treasures from convincing counterfeits.

A Rarity Forged in History’s Crucible

The 1970 penny occupies sacred ground in British numismatics. Unlike its circulation-struck cousins, every 1970-dated penny emerged exclusively as a proof-quality specimen destined for collectors’ sets. This mint-condition origin story gives us three powerful authentication advantages:

• Authentic examples boast razor-sharp strikes with mirror-like fields
• Genuine errors defied the Mint’s notoriously strict proof quality control
• Fakers struggle to replicate that distinctive proof luster and cameo contrast

True double obverse errors (both sides bearing Her Majesty’s portrait) occur when a struck coin adheres to a die, stamping its design onto a fresh blank. With Royal Mint records suggesting fewer than 10 confirmed survivors, this coin’s grail-worthy rarity makes it catnip for sophisticated forgers. Hold that magnifier steady – we’re going in.

The Collector’s Pentagram: Five Authentication Keys

1. Weight: The Gold Standard Test

Your precision scale tells the first chapter of this coin’s story. Every genuine 1970 penny tips the scales at 9.45 grams ± 0.10g – a non-negotiable Royal Mint specification. Consider these sobering realities:

• Forum Specimen: Alarmingly light at 9.225g
• Red Flag Threshold: Anything below 9.35g demands wariness
• Fake Giveaway: Most counterfeits clock in at 9.09-9.30g

That missing 0.225g? In proof coins preserved in mint condition, weight loss from wear is practically unheard of. When your scale whispers doubts, listen.

2. Metallurgy: The Silent Witness

True 1970 pennies sing a specific metallic chorus: 97% copper, 2.5% zinc, 0.5% tin. Arm yourself with these diagnostic tools:

• Magnet Test: Genuine coins show complete indifference to magnets
• Edge Inspection: Seek telltale discoloration where plating meets base metals
• Patina Patterns: Natural toning flows differently on authentic bronze

Modern forgers often use steel cores with copper plating – a fatal flaw that betrays itself when your magnet sticks like a lovesick schoolboy.

3. Die Diagnostics: The Devil’s Playground

Under 10x magnification, the coin’s soul reveals itself. As one sharp-eyed forum member astutely noted:

“At 10 o’clock, the beads are flat at the top and touching the rims. On the bottom one, the beads are round and away from the rim.”

Focus your loupe on these proof-perfect details:

• Denticle Drama: Authentic proofs display uniform, perfectly rounded beads
• Portrait Poetry: Seek the tiny die-polish lines in crown jewels and hair
• Field Finish: Genuine proofs show directional polish lines, not hazy fields

The forum images reveal denticles in disarray – either evidence of forgery or (charitably) the worst proof strike in Royal Mint history.

4. Fakers’ Playbook: How They Try to Fool You

Based on the forum images, we’re likely looking at one of these deception techniques:

• The Hollow Core Con: Machining out one side and inserting a counterfeit obverse
• Electrotype Evil: Copper shells plated over base metal cores
• Spark Erosion Shenanigans: Laser copies that lose critical details

That mysterious arc in image three? It’s likely the ghost of a faker’s seam – a flaw no genuine mint error would bear.

5. When in Doubt: Bring Out the Big Guns

When your eyes and loupe reach their limits, deploy these professional authentication tactics:

• XRF Analysis: The definitive metal composition test
• Ultrasonic Thickness Gauge: Unmasks hollow cores and layered metals
• Specific Gravity: Should hit 8.92 g/cm³ for true bronze
• Electrostatic Testing: Reveals hidden resin fills or bonded seams

Market Realities: Navigating Treacherous Waters

Genuine 1970 double obverse pennies command £4,000-£6,000 at auction – a valuation that attracts sharks. Protect yourself with these essentials:

• Third-Party Slabs: Never buy raw – demand NGC or PCGS certification
• Provenance Pedigree: Trace back to original proof sets when possible
• Dealer Due Diligence: PNG membership isn’t just a badge – it’s a shield

Conclusion: The Thrill of the Hunt

The 1970 double obverse penny represents the pinnacle of modern error collecting – a literal two-headed monarch of British numismatics. While the forum specimen raises red flags (particularly its lightweight profile and troubled denticles), remember this: Every potential discovery fuels our collector’s spirit. Approach such rarities with equal parts passion and skepticism. That £5,000 treasure and £50 curiosity may share nearly identical faces, but their stories – like the finest coins – are written in microscopic details only the trained eye can read. Here’s to your next great discovery – may its provenance be pure and its patina perfect.

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