It's an azalea. Need more info about the 'mold' - is it on the soil and is it mold or dissolved solids left behind on the soil surface as the soil solution evaporates? Usually, if you have fungal growth on the soil surface, it's a fair indication you're keeping the soil too wet, but it depends on what KIND of fungal growth (mold) you're talking about. Al

Saltcedar, thank you so very much!

That appears to be a schefflera arboricola, and the rock-hard thing at the bottom may well be a rock. Root-over-rock plantings are common with this tree. You can keep or remove as you prefer. you can keep it in the same pot if you wish. What are your goals with this bonsai? I ask because it looks very leggy with enlarged leaves, indicating it doesn't get a lot of light. That's neither good nor bad, but with bonsai the goal is usually to keep a plant that is rather compact. This looks like it could use a hard pruning, but I cannot recommend where to cut w/o seeing more of the trunk and primary branches. After that it needs direct sunlight, though maybe some afternoon shade. As to the soil components, put any 5 bonsai growers in the same room and you'll get six different answers about the best soil. I avoid akadama, as it is expensive, relatively hard to get, and most every country in the world has better, local sources to suit the purpose. You can search this site for 'gritty mix'. Mind, this is for succulents, and yours is a tropical that should do well with a larger proportion of organic matter. Post ground level pictures with a white background that shows the trunk and branches, for further advice on pruning.

Thank you. I'll have to wait for flowers to be sure which one I have: Jabily, Elephant tree. Operculicaria decaryi tree. straight pubescent branches and usually red flowers. O. pachpus Eggli 1995, yellow flowers, shrub, zig zag branches I'm going to try to take some cuttings for insurance.