It's not accurate to say that all types of granite are formed by the same combination of minerals. While granite is generally defined as an igneous rock with a specific mineral composition, there is a considerable amount of variation within the family of granites.

Here's why:

* The Major Minerals: All granites typically contain the following minerals:

* Quartz: A glassy, hard mineral that gives granite its sparkle.

* Feldspar: A group of minerals that are typically light-colored and contribute to granite's overall color.

* Mica: A sheet-like mineral that gives granite its often-pronounced texture and can be black (biotite) or silvery-white (muscovite).

* The Variations: While these major minerals are always present, their relative proportions can vary widely, leading to different types of granite. For example:

* Color: Granite can be pink, white, gray, or even black depending on the type and amount of feldspar present.

* Grain Size: Granite can have a fine, medium, or coarse grain size depending on how quickly the magma cooled.

* Other Minerals: Trace amounts of other minerals, like hornblende, garnet, or tourmaline, can also occur and affect the granite's appearance.

To Summarize:

While all granites share the major minerals quartz, feldspar, and mica, their relative proportions and the presence of other minerals create a wide range of granite types, each with its unique appearance and characteristics.