What characteristics for the letter x?

The letter "X" is a consonant in the English alphabet, often representing a sound produced by the combination of the letters "ks." It is commonly associated with themes of mystery, as seen in terms like "X marks the spot," and is frequently used in mathematics to denote an unknown variable. Additionally, "X" can symbolize a cross or a multiplication sign, and it is often used in branding and names to convey a sense of excitement or uniqueness.