Gem wood
From The Blockheads Wiki
Gem wood is a block that makes up gem trees. It cannot be obtained when chopped down. This block was introduced in the 1.6 update.
Appearance
Gem wood has the color of it's corresponding gem.
Where found
Gem wood makes up the trunks of gem trees, which are found on sky islands. It is also found next to gem leaves in the gem tree.