Which gemstone is composed of hydrated silica?

At what temperature (in °C) does diamond turn to graphite?

Which mineral leaves a distinctive red-brown streak when scratched on porcelain?

What percentage of the world's diamonds are gem quality?

What is the primary mineral component of limestone?

Which famous gemstone weighs 45.52 carats and is said to carry a curse?

What is the hardest natural substance on Earth?

What is the Mohs hardness of pure gold?

Which famous ruby weighs 167.97 carats and belongs to the British Crown Jewels?

In what year was the largest diamond ever found, the Cullinan Diamond, discovered?

What is the most abundant mineral in Earth's crust?

What percentage of Earth's mantle is composed of olivine?

Which mineral is known as 'fool's gold'?

At what depth (in km) does the Earth's crust transition to the mantle?

Which mineral is essential for making Portland cement?

What percentage of Earth's crust is composed of oxygen?

Which rock type forms from cooling magma or lava?

What temperature (in degrees Celsius) does quartz crystalize?

Which metamorphic rock forms from limestone under intense heat and pressure?

Which mineral can split into extremely thin, flexible sheets?