Tear Azurite

"This shape-altering component is fundamental to Orokin construction."

- In-Game Description

Forma is a resource used to add, remove, or alter the Polarity of a Mod slot on Warframes, weapons, or Companions; add Tiles to a Clan Dojo; or serve as a component in the creation of certain weapons and items.

Acquisition
Forma or its blueprint can be: Note that the blueprint is consumed when the Forma is crafted.
 * Purchased in the market for or  for a bundle of 3 Forma.
 * Received as a Daily Tribute.
 * Blueprint received as an Alert Reward.
 * Blueprint offered as Invasion battlepay.
 * Blueprint can be found in Void Relics.
 * Blueprint received as a reward from certain Orokin Derelict missions.
 * Blueprint received as a reward from certain Orokin Void missions.
 * Found in Reinforced Orokin storage containers in Orokin Derelict and Orokin Void missions.
 * Received in blueprint form as a Conclave end-of-match reward.

Using Forma on Equipment
To apply a Forma, click Arsenal and equip the desired item. Scroll over the item in the arsenal. Select Action at the bottom of the screen, then choose Polarize, which will show a layout of the item's mod slots and polarities. Click on a slot to cycle through the possible polarities. A slot that already has a polarity (either by default or from a prior polarization) can also be changed.

Forma can only be used on equipment that has already been ranked to 30 and, when used, said equipment is reset to rank 0 (unranked). Warframes and Warframe Skills will be reduced to rank 0. Forma can be used again on already polarized equipment, provided that it is leveled to 30 again. Orokin Catalysts and Orokin Reactors are unaffected by the usage of Forma. Re-leveling equipment after using Forma on it does not grant mastery points.

For each Forma used on equipment, said equipment will gain a star above the name of the equipment starting from the center.

Blueprints Requiring Forma
Click to view the Blueprints requiring Forma. 

Trivia

 * Forma means "shape" in a variety of languages.
 * The prevalence of golden surfaces in Orokin Void levels and on Prime equipment may indicate the use of massive amounts of Forma in their construction. The grey surfaces in the Clan Dojo may be due to Tenno improvising with more mundane materials while copying Orokin aesthetics. The golden colors of the Orokin Reactor may also be due to the presence of Forma in this construct, even though it does not require it for construction.