In 1968, an ossuary was opened and a victim of crucifixion was discovered. He died in the 1st Century AD, around the same time as Jesus in Jerusalem. This is a rare discovery as most victims of crucifixion were left to rot on the cross.
The evidence shows an 11.5 cm nail was driven into the ankle. The tip had fragments of wood. This victim appears to have been crucified on an olive tree.
This could have been because of the lack of suitable trees in the area. Josephus said that the Romans complained about this problem in AD 70, during the Siege of Jerusalem.
If this was the case, then maybe Jesus may have actually been crucified on an olive tree.
Symbolically speaking, this would mean He is the fruit of the olive.
Olives were a very important commodity in the ancient Mediterranean world (and still are). They provided a consistent food source and they were used to anoint kings. Again, symbolically speaking, this means Jesus is the oil who anoints kings.
It would make the symbolism of Jesus praying on the Mount of Olives extremely poignant. Praying amongst the trees he would soon be killed upon.
Fragments of acacia were also found on the other end of the nail. It was likely from a board made from acacia wood. This would have been used to ensure the victim could not slid their feet off the nail.
Acacia was the wood used in making of the Ark of Covenant. Symbolically, this would connect Jesus to the Ark. Again, this is drenched in symbolism.
No other nails were found in the ossuary and so we do not know what wood was used for the cross beam. So it may not have been olive wood. [My wild guess is Ficus sycomorus. This is the type of fig tree mentioned in the Bible. Symbolically, this is the tree of shame].
Having said all of this, according to tradition, Jesus died on a cross made from cedar, pine and cypress. I think this is more likely, as if He died on an olive tree, it would have probably been mentioned by the early Christians.
But if He was, this adds a further dimension to the death and resurrection of Jesus Christ.
This is well within the realm of possibilities. While Christ was required to carry his own cross, this referred to the horizontal piece. The vertical piece is not mentioned and so nailing the cross to a vertical tree would be easy enough to do. The idea is fascinating on so many levels. Tree of Life, Olive tree symbolizing in OT and NT, 'cursed is he who hangs on a tree' Deut 21:22,23...good stuff.