From the bark color and the amount of juvenile foliage, I'd say it's a juniperus media / pfitzeriana. That's a hybrid between chinensis and sabina, with the toxicity of sabina and.. well.. None of the favorable traits of a chinensis.
They are strong and almost indestructible, which makes them great garden plants. For bonsai, their reversal to juvenile foliage is problematic.. You look at them the wrong way and they turn their foliage into needle type.
I'm experimenting with burning instead of clipping, and it seems to circumvent that reversal problem, but it's difficult to do well in tight spaces.
Should be as hardy as junipers get and the foliage does not compact like we see in itoigawa or kishu or blaauw or chinensis. It's more floppy like rocky mountain juniper and virginia juniper.
In essence, you can push these junipers farther than any other juniper and they will bounce back. But even minor clipping can result in a year of juvenile foliage. That's why I'll be buying a battery powered soldering iron tomorrow.
