Ferrite particles, electrophotographic developer carrier core material, electrophotographic developer carrier, and electrophotographic developer

A ferrite particle,

• comprising a crystal phase component comprising a perovskite crystal represented by the compositional formula:
• RZrO3 (provided that R represents an alkaline earth metal element),
• having a surface roughness Rz of 2.0 μm or more and 4.5 μm or less, and
• satisfying the following formulas:
• 6.5≤log H1000≤8.5, and
• 0.80≤log H1000/log H100≤1.00,
• where log H1000:
• logarithmic value (logΩ) of a resistance value H1000 (Ω) of the ferrite particle when an applied voltage of 1,000 V is applied at a distance between electrodes of 2 mm in a high-temperature and high-humidity environment (30° C., relative humidity 80%), and
• log H100:
• logarithmic value (logΩ) of a resistance value H100 (Ω) of the ferrite particle when an applied voltage of 100 V is applied at a distance between electrodes of 2 mm in the high-temperature and high-humidity environment (30° C., relative humidity 80%).