- Microsoft Corporation is an American multinational corporation headquartered in Redmond, Washington, that develops, manufactures, licenses, supports and sells computer software, consumer electronics and personal computers and services. Its best known software products are the Microsoft Windows line of operating systems and Microsoft Office suite. Its flagship hardware products are Xbox game console and the Microsoft Surface series of tablets. It is the world’s largest software maker measured by revenues. It is also one of the world’s most valuable companies.
- Siliceous rock (Wikipedia)
Siliceous rocks are sedimentary rocks that have silica (SiO2) as the principal constituent. The most common siliceous rock is chert; other types include diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, or some types of sponges.