Gemcorns



Gemcorns are a type of Seed whose saplings grow into Gem Trees. They can be crafted from an acorn and a gem. Gemcorns can be planted in the Underground layer or below on Stone, Moss, or any of their biome variants, and the 3 blocks on each side of the planted one must also be one of these. Chopping down a Gem Tree will yield 10-20 Stone Blocks, 0-5 Gemcorns of the tree’s type, and 0-5 Gems of the tree’s type (To be more precise, each tile of the tree has a 1/10 chance of dropping a gem (if it doesn't drop a gem, it'll always drop a stone block), and every leaf tile additionally has a 1/2 chance to drop another gemcorn.)

Farming
Farming gemtrees has proven to be tricky, since it requires an open space in the underground layer or below.

Background Walls
To reduce mob spawning in a Gemtree farm, it is possible to place background walls in almost all of the background, except the two spaces occupied by the placed Gemcorn (this trick is commonly used to make indoors tree farms). Some underground monsters still spawn, but it is far less than a backgroundless farm.

Gemcorns grows in front of fences like normal trees.

Spacing
The Gemcorns must be planted with three tiles of space from other saplings for both to be able to grow.

The height can be 15 tiles, but if the player want to see the canopy of the trees once they grow, it must be at least 17 tiles.

Lighting
Early farmers thought that gem trees would grow faster in the dark, but source-divers have confirmed that in fact the 1.4.0.4 code does not check for light levels at all.

Tips
Painting the block to mark optimal spacing isn't the best option since if placed on a painted block the gemcorn sprouts in a painted gemtree, which is difficult to determine the type of gem. An alternative can be painting the blocks that aren't the ones to plant (like the example in the picture).

The player can toggle smart cursor to automaticaly space the Gemcorn placing to 3 blocks.

Tips

 * Gem Trees can be found naturally in the Underground layer and Cavern layer, although they are rare.
 * Gemcorn saplings cannot be picked up, and are unable to grow in front of background walls except for fence and naturally generated dirt or other underground walls (such as mushroom, lava, dirt, stone, and the underworlds background).
 * Gemcorns should be placed at least 3 blocks apart.
 * Gemcorn trees will grow faster when placed further apart, but times will still vary.
 * Gemcorns can be sold for the value of their respective gem.