The part of the Earth made mostly of silicate minerals is the crust.

Here's why:

* Crust: The outermost layer of the Earth, the crust is composed primarily of igneous, sedimentary, and metamorphic rocks. These rocks are largely made up of silicate minerals like quartz, feldspar, mica, and olivine.

* Mantle: While the mantle is mostly composed of silicate minerals, it also contains significant amounts of iron and magnesium.

* Core: The Earth's core is primarily composed of iron and nickel.

So, while the mantle and even the core contain some silicate minerals, the crust is the part of the Earth where silicate minerals are the most dominant component.