"Sand" usually refers to a substrate with smaller particles than "gravel". Flourite has regular size particles and a "sand" version with smaller particles. "Play sand" tends to include very fine particles, almost like dust, while "pool filter sand" has particles all within one size range, somewhere around 1 mm particles.
With those definitions: the best "sand" for plants is probably Flourite black sand, because of its high CEC. Whether anyone has shown that Flourite black sand grows plants better than pool filter sand I don't know, but theoretically it should.