Alright kiddo, so have you ever heard of a special blue rock called lapis lazuli? It's very pretty and has been used in jewelry and artwork for a long time. Lapis armenus is a type of lapis lazuli that comes specifically from a place called Armenia.
Imagine if you were cooking and you wanted to make a special cake, but instead of using regular flour, you used a special type of flour that came from a very specific place. That's kind of like how lapis armenus works. It's like a special type of flour that comes from a special place.
Now, lapis armenus was especially popular a long time ago when people would use it to make really beautiful and intricate decorations for important buildings, like churches or palaces. Think of it like using frosting to make a cake look really nice. People would use lapis armenus to make big, pretty designs on walls or even in the floors of these important buildings.
Overall, lapis armenus is just a special type of blue rock that came from a certain place and was used to make really pretty decorations a long time ago.