You are not limited to Material icons. Any ImageVector or Painter can be used.

Here the icon is loaded from a drawable resource and displayed at 32 dp size.

If you want the icon to adapt to the current theme, use a color from MaterialTheme:

You can style the icon using the tint parameter:
Changing color

To display a Material icon, you can use the Icons.Default collection.

The contentDescription parameter is important for accessibility. If the icon is purely decorative you can pass null.