This is the 17162nd most frequent Russian word.
стеклянных
"Made of glass" or "glass (adjective)."
Here, 'стеклянных' describes the material of the panels, stating that they are made of glass.
Я смотрю через чистое окно из стеклянных панелей.
I look through a clean window made of glass panels.
In this sentence, 'стеклянных' emphasizes the material of the bottles, indicating they are glass.
В музее я увидел коллекцию старинных стеклянных бутылок.
In the museum, I saw a collection of antique glass bottles.
The word 'стеклянных' here qualifies the pendants, specifying their material as glass.