What are Covenant Ships made of!?

A size comparison of some of Halo's ships : r/halo

The Forgotten Human Destroyer, Hillsborough-Class Heavy Destroyer

The Forgotten Human Destroyer, Hillsborough-Class Heavy Destroyer

Interior of Covenant Boarding Craft

The History of Halo's Scorpion Tank

Halo Lore - The True Effects of Covenant Glassings

We Bullied Each Other In Halo: ODST

Mjern-pattern agricultural support ship - Ship class - Halopedia, the Halo wiki

Covenant starship - Halopedia, the Halo wiki

Halo Reach- Nightfall: Discovering the Covenant Invasion Force

What are Covenant Ships made of!?