Glass
A flat transparent substrate provides a smooth, rigid surface.
Mendeleev
Mendeleev.com · Objects
What is a mirror made of?
The glass gives the mirror its shape; a very thin metal layer does most of the reflecting.
Layer by layer
Reflective metal
Common mirrors use a thin reflective coating, often silver or aluminium depending on the design.
Protective layers
Paints or other coatings protect the reflective layer from scratches, moisture and chemical attack.
The familiar household mirror is a layered object. Light passes through the front glass, reflects at the metal coating and travels back out.
Why combine materials?
Real products rarely ask one material to do everything. Strength, corrosion resistance, thermal behaviour, appearance, cost and manufacturing can point to different choices, so layers and alloys are often more useful than a single pure substance.
Why this object uses several materials
Most manufactured objects solve several problems at once: strength, electrical conduction, thermal behaviour, corrosion resistance, weight, appearance and cost. One pure material rarely satisfies all of them.
That is why a useful way to read an object is part by part. Each component reveals a different compromise between chemistry, physics and engineering.
What changes in practice
Real examples often add one more layer: geometry, impurities, coatings, humidity, flow or manufacturing history can alter what you observe even when the main mechanism is unchanged.
That is why two objects made from broadly similar materials can behave differently. The useful question is not only “what is it made of?” but also “how is it built, under what conditions, and for which function?”