I have an idea for an SCP. It's a word written on a type of paper. I know we have a few of these floating around but here is my take on it.
1) The word is not memetic nor sentient.
2) It's rather recent, with the first reported case of a death caused by the word to have occurred in the 70's.
3) The word was found written in the journal of an amateur poet, who was found dead in the room with the word.
4) The original iteration of the word is written in a handwriting of someone other than the poet, implying that someone out there still knows the word.
5) Speaking the word will turn anyone within earshot to turn to stone from the inside out, starting with bones. The process is extremely painful and fast, and always ends in death.
6) The written word itself is safe. It's only when the word is heard out loud that the effects take hold. Recordings of the word are just as fatal, but deaf individuals are immune.
I would classify this as Euclid, with most of the Foundation efforts in the subject directed at finding the individual who originally wrote it in the journal. It might also be used as either a last resort by captured SCP agents or specially trained deaf agents in the field. What do you guys think?