Quandong fruit trees are native to Australia and vary in size from 7 to 25 feet (2.1 to 7.6 m.) in height. Growing quandong fruit is found in the semi-arid regions of Southern Australia and are tolerant of both drought and salinity. Trees have drooping, leathery, light grey-green foliage. Insignificant greenish blossoms appear in clusters from October to March
To Germinate: There are several ways of germinating Quandong, but the main thing here is HEAT. One method is to put your seeds on a tray and leave out in the heat 35 + degrees and bake in the sun. This is to enable the seed's outer shell to crack as there is a kernel inside. This kernel is where the seedling emerges from. Once your seeds have cracked, soak them for 24 hr, and then you can put them in a soil mixture of mixed top soil/clay/seed raising mix and leave in full sun, watering when soil has dried out. 
Another method (if you're game enough) is to crack the seeds in some type of vice, forcibly creating a crack in the shell. Once you have achieved this, soak in water overnight and put in soil. Or otherwise, you can put them in soil straight away in full sun, and let Mother Nature do the rest.