Required Fields will never have a default value, empty defaults means null.

All Fields can be set via setName e.g. block.setUnlocalizedName("name"); and gotten via getName;

Nombre	Type	Required	Default Value	Notes
Nombre axisAlignedBB	Type MCAxisAlignedBB	Required No	Default Value Full Block	Notes Lets you set the block's bounding box
Nombre beaconBase	Type boolean	Required No	Default Value false	Notes Can this block be used as part of a beacon's base?
Nombre blockColorSupplier	Type IBlockColorSupplier	Required No	Default Value -1 as color	Notes The block's color
Nombre blockHardness	Type float	Required No	Default Value 5.0	Notes How long it takes to break
Nombre blockLayer	Type String	Required No	Default Value "SOLID"	Notes "SOLID", "CUTOUT_MIPPED", "CUTOUT", "TRANSLUCENT"
Nombre blockMaterial	Type IMaterialDefinition	Required No	Default Value Iron	Notes The Block's base material
Nombre blockResistance	Type float	Required No	Default Value 5.0	Notes Explosion resistance
Nombre blockSoundType	Type SoundType	Required No	Default Value Metal	Notes The Block's sound type (determines things like the breaking sound)
Nombre creativeTab	Type CreativeTab	Required No	Default Value Misc	Notes The Creative tab the item will appear in
Nombre dropHandler	Type IBlockDropHandler	Required No	Default Value ​	Notes What the block will drop when broken
Nombre entitySpawnable	Type boolean	Required No	Default Value true	Notes Can be used to prevent any entities from spawning on this block
Nombre enumBlockRenderType	Type String	Required No	Default Value "MODEL"	Notes "INVISIBLE", "LIQUID", "ENTITYBLOCK_ANIMATED", "MODEL" → Sets how the block is rendered
Nombre fullBlock	Type boolean	Required No	Default Value True	Notes Used for rendering and light calculations
Nombre gravity	Type boolean	Required No	Default Value false	Notes Is this block affected by gravity
Nombre itemColorSupplier	Type IItemColorSupplier	Required No	Default Value -1 as color	Notes The block's color when it is in item form
Nombre lightOpacity	Type int	Required No	Default Value 255 if fullBlock is true or 0	Notes Does Light pass through
Nombre lightValue	Type int	Required No	Default Value 0	Notes Light level of block, ranges from 0-1. This value is multiplied by 15 to determine the final value.
Nombre onBlockBreak	Type IBlockAction	Required No	Default Value ​	Notes Called when Block is broken.
Nombre onBlockPlace	Type IBlockAction	Required No	Default Value ​	Notes Called when Block is placed.
Nombre onRandomTick	Type IBlockAction	Required No	Default Value ​	Notes Called on a random tick event.
Nombre onUpdateTick	Type IBlockAction	Required No	Default Value ​	Notes Called when Block receives a block update.
Nombre passable	Type boolean	Required No	Default Value Depending on the IMaterialDefinition provided	Notes Can players pass through this block?
Nombre replaceable	Type boolean	Required No	Default Value Depending on the IMaterialDefinition provided	Notes Can this block be replaced by another block?
Nombre slipperiness	Type float	Required No	Default Value 0.6f	Notes Ice blocks are 0.98f
Nombre textureLocation	Type CTResourceLocation	Required No	Default Value null	Notes The block's resource location, used for textures etc.
Nombre toolClass	Type String	Required No	Default Value pickaxe	Notes Tool required to Break Block
Nombre toolLevel	Type int	Required No	Default Value 2	Notes Tool Level required to Break Block
Nombre translucent	Type boolean	Required No	Default Value false	Notes Is see through
Nombre unlocalizedName	Type String	Required Yes	Default Value ​	Notes Name, should be all lowercase
Nombre witherProof	Type boolean	Required No	Default Value false	Notes Can Wither's destroy this block

ZenScript
 Copy
#loader contenttweaker

import mods.contenttweaker.VanillaFactory;
import mods.contenttweaker.Block;

var antiIceBlock = VanillaFactory.createBlock("anti_ice", <blockmaterial:ice>);
antiIceBlock.setLightOpacity(3);
antiIceBlock.setLightValue(0);
antiIceBlock.setBlockHardness(5.0);
antiIceBlock.setBlockResistance(5.0);
antiIceBlock.setToolClass("pickaxe");
antiIceBlock.setToolLevel(0);
antiIceBlock.setBlockSoundType(<soundtype:snow>);
antiIceBlock.setSlipperiness(0.3);
antiIceBlock.register();

You will need to add tile.contenttweaker.blockName.name=Localized Name to the responding language files.
If you have doubts, take a look at the display name of the item when you're holding it before translating it.

Alternatively, you could use CraftTweaker's localization feature, though it's recommended using the language files!