They are impossible to destroy...
Religious opinion on the preservation of the coccyx bone and the resurrection of people from it
Belief in the Day of Judgment and the resurrection of all creations to account to the Creator is one of the most important pillars of religion for a true believer.
Ibnu Kathir in his interpretation (tafsir) of the Koran says that one day As ibn Wa’il came to the Prophet ﷺ with decayed bones and, having crushed them in front of him, mockingly asked, “Will Allah ﷻ revive the bones that you see in my hand?” To which the Messenger of Allah ﷺ replied, “Yes, Almighty Allah will kill you, then resurrect you and you will enter Hell.”
On this occasion, the Almighty sent down a revelation (the meaning of the commentary on ayat 78–79 of Sura Ya-sin): “He gave Us an example, forgetting where he came from. He asked: “Who will revive the decayed bones?” Answer: “The One who created them the first time will revive them. He knows (everything) about each creation.”
If the Almighty Creator created the heavens and the earth, the entire Universe, then He is even more capable of creating people and resurrecting them after death.
It is narrated from Abu Hurairah that the Messenger of the Almighty ﷺ said, “Between the two blows (he is talking about blowing on the horn of the angel Israfil, which is one of the great signs of the coming of the Hour of Judgement) there are forty years. Then Allah ﷻ will send down water (rain) from the sky and people will sprout like lentils. The entire human body decays except for one bone - the tip of the tail (coccyx). From it, every creation will be restored on the Day of Judgment.” (Narrated by Al-Bukhari, Muslim).
Another version of this hadith says that the Messenger of God said: “Every person (the son of Adam) is eaten by the earth (the whole body decomposes in the earth), except for a small particle at the end of the spine (the tailbone). From it, man was created and from it, his body will be restored.” (Narrated by Al-Bukhari, Ahmad, An-Nasai).
Undoubtedly, the Almighty Creator, who once created man from nothing, can easily repeat this again - even without the tailbone - because His power is limitless.