This grower is sure of this plant identification.
Lithops species native to Namibia
Living stones, Pebble plant, Stone plant, Flowering stones
Lithops genus (Living stones). These are prostrate, egg-shaped, perennial succulents. They produce a fissure from which a white or yellow daisy-like flower emerges. Each pair of old leaves will split and dry away to papery skin to reveal a pair of new leaves growing at right angles to the old ones.
These frost-tender succulents are easy to grow but require very dry conditions, so need to be kept under shelter in all but arid climates. Plant in coarse, gritty soil and allow full sun. Water only in spring and propagate in summer from seed or by dividing bodies and treating them like cuttings.