Spruce Leaves are obtained from Spruce Trees. To collect leaves, the player must have something with the silk touch enchantment. If the silk touch enchantment is used, the player will obtain the leaves. If the enchantment is not used, the leaves will be destroyed with a possibility of giving a sapling. Leaves will disinigrate if all the wood in a tree is removed with an axe or any other tool. The only other way to get leaves other than silk touch is by using creative mode.
Oak Leaves are blocks with Opacity. Blocks with Opacity are not "fully complete" blocks or have transparency. For some of these blocks, it may not be possible to place other types of blocks directly onto them. Blocks with Opacity are as follows: Water (Source), Lava (Source), Tall Grass, Oak Sapling, Birch Sapling, Spruce Sapling, Jungle Sapling, Red Mushroom, Brown Mushroom, Red Flower, Dandelion, Crops, Sugar Cane, Cactus, End Portal, Portal, Fire, Sign, Torch, Snow, Air, Enchantment Table, Redstone Torch, Redstone Wire, Button, Pressure Plate, Lever, Rail, Trapdoor, Redstone Repeater, Door, Iron Door, Bed, Cake, Fence, Ladder, Oak Wood Stairs, Spruce Wood Stairs, Jungle Wood Stairs, Birch Wood Stairs, Cobblestone Stairs, Bricks Stairs, Stone Brick Stairs, Nether Brick Stairs, Sandstone Stairs, Quartz Stairs, Stone Slab, Sandstone Slab, Cobblestone Slab, Bricks Slab, Stone Brick Slab, Oak Wood Slab, Jungle Wood Slab, Birch Wood Slab, Spruce Wood Slab, Nether Brick Slab, Quartz Slab, Farmland, Chest, Large Chest, Glowstone, Piston, Sticky Piston, Oak Leaves, Jungle Leaves, Spruce Leaves, Birch Leaves, Glass, and Ice.