Learn Spanish (Latin America): La cadena tiene un colgante muy extraño.

You would place sí que directly before the conjugated verb tiene. The sentence becomes La cadena sí que tiene un colgante muy extraño (The chain really does have a very strange pendant). You use this structure to emphasize the fact, especially to counter someone who previously doubted that the pendant was strange.

Is colgante derived from a verb?

Yes, colgante comes from the verb colgar, which means to hang. While it functions here as a noun meaning pendant (a hanging piece of jewelry), it is also a common adjective for things that are suspended, like un puente colgante (a suspension bridge).

What is the difference between extraño and raro in this context?

There is virtually no difference here. In everyday Latin American Spanish, raro and extraño are used interchangeably to describe something weird, unusual, or strange. Saying un colgante muy raro would be just as common and mean exactly the same thing.

Does cadena only refer to physical chains like jewelry?