In 1990, Portugal issued several 100 escudos coins, each with different themes, designs, and mintages. There are at least three main varieties relevant to collectors:

1. 100 Escudos – “Pedro Nunes” (bimetallic)
2. 100 Escudos – “Astronomical Navigation” / “Conquest of the Atlantic”
3. 100 Escudos – “Restoration of Independence (1640‑1990)”
4. 100 Escudos – “Camilo Castelo Branco”, commemorating the centenary of his death.

Each coin has distinct physical characteristics and numismatic value.

Technical Features of the Coins

1. “Pedro Nunes” (bimetallic)

• Composition: bimetallic — aluminum-bronze core with a cupronickel ring.
• Diameter: ~25.5 mm.
• Weight: ~8.3 g.
• Edge: reeded (partially serrated depending on the edition).
• KM (Krause catalog): KM 645
• Theme: portrait of Pedro Nunes, a famous Portuguese mathematician and cosmographer.

2. “Astronomical Navigation” (“Conquest of the Atlantic”)

• Composition: cupronickel.
• Diameter: ~33.8 mm.
• Weight: 16.5 g.
• Thickness: ~2.4 mm.
• Edge: smooth / milled.
• Theme: highlights Portuguese astronomical navigation, with stars, solar winds, and a stylized ship.
• KM: KM 649

3. “Restoration of Independence (1640‑1990)”

• Composition: cupronickel.
• Diameter: 33 mm.
• Weight: 15.1 g.
• Thickness: 2.8 mm.
• Edge: milled.
• Theme: commemorates 350 years of the Restoration of Portuguese Independence (1640‑1990), featuring a figure with a sword symbolizing independence.
• KM: KM 651
• Engraver: António Marinho

4. “Camilo Castelo Branco”

• Composition: cupronickel.
• Diameter: ~33–34 mm.
• Weight: ~15–16.6 g depending on sources.
• Edge: reeded or milled.
• Theme: portrait of Camilo Castelo Branco (1825‑1890), commemorating the centenary of his death.
• KM: KM 656

Mintage and Circulation

• The mintage of some regular 100 Escudos coins from 1990 was around 52,000,000.
• These coins were part of regular or semi-commemorative circulation, depending on the version. For example, the bimetallic “Pedro Nunes” version circulated normally, while others were mainly commemorative or collectible.

Numismatic Value

The market value of these coins depends heavily on their condition and the specific variety. Approximate estimates:

• Common 1990 100 Escudos coins: €0.47 to ~€0.92 for circulated conditions.
• Higher-grade (UNC, XF, BU) coins can command higher prices depending on demand and variant.

Examples from auction listings:

• 100 Escudos 1990 common: ~€11.22 (EF condition)
• 100 Escudos 1990 BU: ~€22.55
• 100 Escudos 1990 Camilo Castelo Branco: ~€6.09

Prices vary according to condition, seller, and market demand.

Historical and Numismatic Importance

1. Commemoration of important figures: Pedro Nunes (science and navigation) and Camilo Castelo Branco (literature) make these coins appealing to collectors and cultural enthusiasts.
2. Key Portuguese themes: “Astronomical Navigation” celebrates the Age of Discoveries, while “Restoration of Independence” recalls a crucial historical moment (1640).
3. High mintage but still collectible: Despite large mintages, the diversity of variants maintains collector interest.
4. Monetary transition: These coins are part of the final era of the Portuguese escudo before the adoption of the euro in 2002, adding historical value.

Conclusion

The 1990 100 Escudos coin from Portugal is not unique—there are multiple commemorative versions, each with its own theme, composition, and mintage. While many coins are relatively common, they are interesting to collectors for their historical symbolism and design.

The value depends on:

• The specific variant you own (Pedro Nunes, Astronomical Navigation, Restoration, Camilo, etc.)
• Condition (worn, very fine, almost new, etc.)
• Whether it is uncirculated or proof
• Current collector demand