Tie pin
A tie pin was a small piece of jewelry used to fasten a necktie. 

In one of Arthur Conan Doyle's Sherlock Holmes stories, Queen Victoria gave Holmes an emerald tie pin as a reward for solving the theft of the Bruce-Partington plans. 

In 2365, Data showed Geordi La Forge this object as an example of the collected possessions Holmes considered significant. ()

See also 
 Tie bar

External link 
 

de:Krawattennadel
Clothing accessories