809: Derivations of 'Petra' Feb 24, 2017

What do being terrified, the smell after it rains, a chemical used in fertilizers, and the keeper of Heaven have in common? The answer is that they all relate etymologically to rocks. The word in Latin that meant, 'rock', 'petra' came from a Greek word first, and these together developed into a number of English words. If someone is unable to move and therefore acts in a rock-like manner out of fear or surprise, this is to be 'petrified', and also refers to when organic matter becomes stony after being gradually replaced by mineral deposits. 'Petrichor', meanwhile, is the smell after it rains, and it is thought that this is caused by water coming in contact with compounds in the ground. You can see more on that here. Likewise, 'saltpeter', and the names 'Peter' and 'Pierre' come from this same root. In fact, St. Peter was born, Simon, but was given his name by Jesus to signify the rock on top of which he would build a church; the name is still quite common today. Don't be fooled by other words like 'petri dish', because some relationships are coincidental, however.