This is a succulent I have had for a long time and lost the identification tag a long time ago, but I think it is a pachyphytum or a graptopetalum, or a cross of the two. Or something else, perhaps! I just know I like it.
Pachyphytums are native to Mexico, and I like them for their fleshy, glowing leaves which take on a hint of pink or red from exposure to the sunlight. They have a pretty little yellow flower, but the fleshy growth is why I have it. Given the right amount of sun, it turns redder and makes a compact, full plant that will have some branches cascading out of the pot in the manner of donkey tail.
I like it better as a specimen plant rather than in a grouping in a dish garden because it will fill the pot nicely. But use it however you please. You will enjoy the fat leaves and color. Just make sure it gets enough sun; it isn’t pretty when it starts reaching for light.