Jain belief does not teach that the age of an idol makes it miraculous.

• Idols are symbolic representations of the Tirthankaras and serve as focal points for reverence, not as magical objects by themselves. The power or miracles come from the jiva (soul) and its karma, not from the physical age of the idol.
• Miraculous powers (siddhis) in Jainism are associated with the spiritual attainment of a liberated soul, or with the deep, disciplined practice of a realized being. The material statue’s age does not grant or enhance those powers.
• Different Jain traditions (Digambar and Shwetambar) may have variations in how idols are worshiped or consecrated, but both regard the idol as a symbol, not as an inherently miraculous object.
• Antiquity of an idol within a temple may add to its historical and devotional significance, which can inspire faith and devotion, but that significance is about reverence and continuity of practice, not about an intrinsic miraculous attribute due to age.

If you want, I can explain how Digambar and Shwetambar perspectives differ on idol worship and consecration.