When the Earth Federation designed the RX-78 series of mobile suits, they also wanted a material that was strong, lightweight and durable for its construction; at that time they did not possess an adequate number of facilities to effect very-large-scale production and maintenance. Titanium isn't considered ideal as it becomes brittle if subjected to large amounts of stress over time as well as being slightly more complicated to work and weld when compared to other alloys like Steel, prompting the engineers to develop a new lightweight alloy that eventually came into being U.C. 0064, known as Luna titanium.
- Gundarium α
- Gundarium α (Alpha) is the first of three reproduced Luna Titanium alloy variants developed at Axis and in secret by the Anaheim Electronics company. It was known to have been used in the construction of the MSA-003 Nemo. This alloy is essentially an exact reproduction of the original Luna Titanium alloy used in the V Project prototypes.
- Gundarium β
- Gundarium β (Beta) is the second of three reproduced Luna Titanium alloy variants developed at Axis. It represents the intermediate stage of development between Gundarium α and Gundarium γ (Gamma).
- Gundarium γ
- Gundarium γ (Gamma) is the third of three reproduced Luna Titanium alloy variants developed at Axis. Introduced in U.C. 0087, it was lightweight and featured excellent durability, making it widely adopted on second generation mobile suits used in the Gryps Conflict. The introduction of Gundarium γ also presented technological advances in MS development, including the mass production of transformable (variable) mobile weapons was also realized.
- Gundarium ε
- Gundarium ε (Epsilon). Developed by Anaheim Electronics, it was essential in the construction of the Epsy Gundam, which used a nuclear pulse propulsion system.
- Gundarium Alloy/Ceramic Composite
- Introduced in the U.C. 120s following the progress in the miniaturization of mobile suits. This material added a ceramic composite material similar to the earlier armor's used on mobile suit's during the mid to late UC 0080's and UC 0090's. With the advent of miniaturized mobile suits in the early U.C. 0100's, multiple mass production suits (such as the RGM-109 Heavygun) could be made out of Gundarium for the price of a single mobile suit of an older design. Unfortunately, the hybridization of Gundarium and Ceramic composites degraded the protective qualities of Gundarium. Combined with the thinner armor on the miniaturized mobile suits, this meant that while mass production mobile suits were armored with Gundarium instead of a cheaper Titanium/Ceramic based composite; they were more vulnerable to physical attacks, whereas the older prototype mobile suits with pure (and thicker) Gundarium armor were almost impervious to attacks that would severely damage or destroy the former.
The Luna Titanium armored RX-78-2 Gundam was almost unstoppable in combat. 120mm and 90mm shells fired from the Zaku's machine guns having almost no effect on it. Physical attacks such as blunt force had little effect as well. During a fight with the Gundam on Luna II, Zeon pilot Char Aznable said that he "hadn't seen a mobile suit that could survive the beating I'm giving it" despite the fact that he had knocked the machine around using melee techniques.
The alloy had some degree of resilience against mega particle weapons as well; following a duel with Zeon's Zeong at A Baoa Qu, the Gundam was shown to only have lost its head, left arm, and later part of its right leg, but otherwise showed little damage. During the events of Operation Stardust, the RX-78GP01 Gundam "Zephyranthes" was sortied hastily resulting in it's near-destruction at the hands of Zeon remnants; however, while the Gundam suffered damage to it's head, right shoulder, and lost it's left arm and one of it's legs, direct hits to the torso from a handheld beam weapon did not destroy it. Another similar case was during the events of Char's Counterattack, in this instance Char's MSN-04 Sazabi was struck by a beam weapon in its midsection, only chipping off a few tiny pieces as a result.
- Lightweight: the Gundam was taller than the Zeon Zaku by about a meter, but the shorter Zeon mobile suit weighed slightly more than the Gundam.
- Durable: projectile weapons could only scratch the alloy, which proved to be a disadvantage as most Zeon mobile suits were only equipped with machine guns or 280mm bazookas. (The 360mm Bazooka used by the MS-09B Dom had the ability to do moderate damage due to the large explosive charge, but the shells could easily be evaded at long range.)
Despite its effective qualities, Luna Titanium alloy was plagued by several problems:
- Expensive: the RGM-79 GM couldn't be made from this armor because it required a long time to refine and extract the ore, which made it impractical for mass production. Even though the mass-produced RX-79［G］ Gundam Ground Types were armored with Luna titanium alloy, it was only in the vital areas that this durable alloy could be found.
- Repairs: the unique durability of this alloy troubled Federation mechanics as much as Zeon troops since expedient repairs that involve first steps such as cutting open or welding external armor plating proved impossible using equipment readily available in the field. In effect, the White Base, Jaburo and Luna II were the only locations that had the facilities required to repair and maintain the V Project prototypes.
- After the One Year War, this alloy was renamed Gundarium in honor of the RX-78 and its pilot's exploits during the war. A similarly-named alloy known as Gundanium Alloy appears in the series Mobile Suit Gundam Wing. Like Luna Titanium, it is a lightweight yet strong material used to construct Gundams. However, unlike Luna Titanium, Gundanium is shown to be almost completely indestructible and needs to be artificially assembled in space.
- In a very obscure Easter egg in Gundam Wing on a computer screen shown during Quatre's exploration of the Sandrock's development program) Gundanium Alloy is identified as "Gundarium Theta." This could simply be a joke made by the show's producers.