EN
We study order convexity and concavity of quasi-Banach Lorentz spaces $Λ_{p,w}$, where 0 < p < ∞ and w is a locally integrable positive weight function. We show first that $Λ_{p,w}$ contains an order isomorphic copy of $l^{p}$. We then present complete criteria for lattice convexity and concavity as well as for upper and lower estimates for $Λ_{p,w}$. We conclude with a characterization of the type and cotype of $Λ_{p,w}$ in the case when $Λ_{p,w}$ is a normable space.