Currently, there are three main types of proppants

Currently, there are three main types of proppants: frac sand, resin coated proppant (RCP), and ceramic proppants. Each proppant type has its own advantages and disadvantages, and reservoir engineers decide on the type to be used depending on geology, availability, prices, and Government regulations.
In 1947, first fracturing was done with fracturing resin coated silica sand. Fracturing sand is the basic type of proppant material and is being used since the first fracturing. The R&D on proppant resulted in two comparatively new proppants named resin coated proppants and ceramic proppants. Frac sand is low price untreated sand proppant with lowest conductivity among the three. Ceramic proppants and resin coated proppants are high quality, high strength, and high conductivity proppants; and are used in very low permeability wells or in multiple stages fracturing. Non-grain proppants like CO2, N2, and LPG are on the horizon but will take long time to get commercialized.