  A more fundamental task is the enumeration of atomic properties. Gassendi distinguishes between two sorts: those properties inherent in and essential to all individual atoms, and those which are a feature of atoms in groups. His list of inherent atomic features, which closely follows Epicurus's list, includes: extension, size (moles, or more recognizably, magnitudo), shape (figura), weight or mass (pondus), and solidity (soliditas). Relative to each of these features all atoms generally resemble one another, there being a limited range of sizes and weights. One exception is shape. In order to account for tremendous variety among natural objects, Gassendi claims, there must be very many different types of atomic shapes (though not infinitely so), and many tokens of each type (again, not infinitely so).