On a sort of pedantic note, scholars refer to them as "The Maya" and not "Mayans." This is the generally accepted way to refer to them, both according to modern-day descendants and to academics.

Anyway, it depends on what sorts of tools we're talking about, and in what contexts. However, people in many areas in the Maya world utilised a material called chert (also sometimes known as flint, which is a close mineral cousin). It was used for things like hand axes, blades, bifaces, projectile points, et cetera. It has a particular mineral composition that is both very strong and able to be finely flaked because of its fine-grained silica-based microcrystalline structure. Like glass, which is also silica-based, it fractures and does so in a predictable way. This is in contrast to other types of stone from the area, such as limestone, which is soft and good for carving but will not flake--rather, it will crumble. Chert is the same material that other groups across the world--including early modern humans and neanderthals in Europe--harvested to make their tools.

There were several sources where this material was obtained and traded all around Mesoamerica. One example is the site of Colha in Northern Belize, which sits on a massive high quality chert outcrop--Belize's so-called chert-bearing zone-- and shows evidence of a heavy tool production industry. Chert was an important material but it was not available everywhere.

Another common material, though imbued with more value and ritual significance, was obsidian. That is, volcanic glass. This can be obtained from volcanic areas. In this case it was mostly obtained in the Guatemalan Highlands (e.g. El Chayal or Ixtepeque) and traded around Mesoamerica. Obsidian is essentially black glass but made stronger by its "impurities." It can be flaked to make EXTREMELY sharp tools to the point of surgical grade sharpness. It is known to be "stronger than steel" and its products can even sharper than surgical grade tools when made by a master. In fact, it was often used (in the form of microblades) in bloodletting activities. Reminiscent of a scalpel. I do Maya archaeology and have found these blades before--they can look almost manufactured when well-made.

Obsidian can also be used to make larger blades or knives, scrapers, or any manner of items. Sometimes certain pieces that came off during the core reduction process, known as "eccentrics," would be made into special ritual and artistic items. Here you can see a famous eccentric into which a facial profile and other forms were flaked.

In general, obsidian was used in both daily activity by common peoples and also by elites, who somewhat restricted its access. However, we are coming to find that the average person had more access to it than archaeologists once thought.

There are other materials used by the Maya to make things (e.g. basalt for hammer stones and other things, especially in the Guatemalan highlands) but the above two are common and most well-known.