Silver-white copper alloy and method of producing silver-white copper alloy

A silver-white copper alloy comprising:

• 51.0 mass % to 58.0 mass % of Cu;
• 9.0 mass % to 12.5 mass % of Ni;
• 0.05 mass % to 1.9 mass % of Mn;
• 0.0003 mass % to 0.010 mass % of C;
• 0.0005 mass % to 0.030 mass % of Pb;
• and
• the balance of Zn and inevitable impurities,
• wherein a relationship of 65.5≦[Cu]+1.2×[Ni]+0.4×[Mn]≦70.0 is satisfied between a content of Cu [Cu] (mass %), a content of Ni [Ni] (mass %), and a content of Mn [Mn] (mass %), and
• in a metal structure thereof, an area ratio of β phases dispersed in an α-phase matrix is 0% to 0.9%.

A silver-white copper alloy comprising:

• 51.5 mass % to 57.0 mass % of Cu;
• 10.0 mass % to 12.0 mass % of Ni;
• 0.05 mass % to 0.9 mass % of Mn;
• 0.0005 mass % to 0.008 mass % of C;
• 0.001 mass % to 0.009 mass % of Pb;
• and
• the balance of Zn and inevitable impurities,
• wherein a relationship of 66.0≦[Cu]+1.2×[Ni]+0.4×[Mn]≦69.0 is satisfied between a content of Cu [Cu] (mass %), a content of Ni [Ni] (mass %), and a content of Mn [Mn] (mass %), and
• in a metal structure thereof, an area ratio of β phases dispersed in an α-phase matrix is 0% to 0.4%.