I'm not sure what a synthetic rock is? Concrete? Natural rocks and minerals I do have some knowledge of and I know of no reason they couldn't last a few billion years.
Sounds like another wrong answer of an antiChristian.
Else where is your scientific evidence? Can you show me a 100 yr-old rock, 1000 yr-old rock, 10,000 yr-old rock, 1 million yr-old rock, 100 million yr-old rock, 1 billion yr-old rock, and 4.5 billion yr-old rock to compare? Where were these rocks found to see their environment and compare it with other rocks there.
![www.nsf.gov](https://www.nsf.gov/news/mmg/media/images/oldest_rock1_f1.jpg)