Heart of Iron on my Mega Gem not working?

Hi, can i check does heart of Iron add to Armour or Life? i tried to equip the skill on the gem but no response.
Am i wrong or it is a bug? Thanks.
Appreciate and advice or feedback.

Heart of Iron
Small cluster jewel Notable
Gain 10% of Life as extra Armor

Since it's a notable, you can't "link it to a gem", only Support Gems can be linked to a Skill Gem. If any, you have socketed your Cluster Jewel with Heart of Iron in one of your Outer Jewel socket in your passive tree AND allocated it spending passive skill point (just like you allocate any other node on your tree)

The effect states that by allocating this node you will gain global base armour equal to a 10% of your life. So, if you have 5000 life, you will gain a 500 base armour.
This base armour is global: it will not be increased by "+x% increased armour" bonus on your equipment (for example, the +600% increased Armour on a Brass Dome"), nor by putting quality on your item, since both of these things applies only to that specific piece of equipment.
It will, however, be increased by any "+x% increased armour" from your passive nodes (included notables like Cloth and Chain) and by bonus that specifically increases your global defences (like Skin of the Lords/Loyal)

Hi,

it is to a jewel. the issue is i view on pob and there is no increased on any stats.

what i understand from your message is this is global on a jewel and it will not be seen anywhere? just to confirm.

thanks.