Gain access to the Shield and False Life Spell naturally, which does not cost a Spell Slot to cast but can only be casted once per Short or Long Rest. 

Somewhere embedded into your body, such as your torso, forehead, hand, foot, ankle, etc. is a crystal gem of a various type. 

Though you are a construct, you are a living creature. You are immune to poison, diseases, and the effects of aging. You are do not need to eat, breathe, or sleep, though you may choose to ingest food and drink if you wish although the food or drink you consume do not cause effects if any are intended. 

When your Hit Points reach 0 and you fall unconscious or if you are magically made unconscious, you withdraw. Rather than falling limp to the ground, your body retreats into the gemstone, in which you do not drop all your items onto the ground and you don't make death saves but you can also choose to willingly withdraw into the gemstone regardless of being unconscious. The gem will use your AC and if hit, counts normally to your death saves as a fail. You still can be healed back to consciousness as normal. However, medical kits do not affect you and you may be stabilized with an Arcana check, or the spell Mending, with a DC of 10. You reform from your gemstone 2 minutes after you stabilize so long as you have room to do so around 5 feet in area and you have not taken a failed death save in your withdrawn gen state within the previous 5 general turns. 

A single weapon type (such as sword, axe, bow, crossbow, firearm, gauntlets, etc.) is selected as your character's iconic and unique-to-them weapon. Your character can ONLY wield weapons of the type you choose and can summon it or desummon it at will without spending an Action. It can also never be knocked from your hands, as it will simply desummon into your gem. 

You gain the following benefits while wielding your Legendary Weapon. You gain +1 AC, all of your Stats gain a +2 bonus, and you have an extra 1d4 melee damage per level with it equipped. 

Your Wisdom and Dexterity will increase by 1 point each and your Constitution will increase by 2 points. 

You have a natural storage. You can store up to five items or armors at once. You summon the chosen item from your gem as a bonus action and can put it back as an action. When you fall unconscious, the items are still inside of your gemstone but when you die, the items are released from your gem within 10 ft of you but are all corrupted and unusable. 

Until now, you have been an undefined gem that looks similar to one you can now select within this Trait. 

Pearl: Pearls appear to be extremely loyal servants. They obey any task given by their master and generally don't cause insurgencies, though it has been known to happen. 
Ability Score Increase. Your Wisdom increases by 2 points. 
Pearl's Library. You can do anything to improve your working efficiency for certain things. As part of the same action, you can gain Advantage in any ability check a number of times equal to your proficiency bonus. 
Eternal Servitude. A pearl must have a master. Your master can be anyone that she was designed to obey when created, such another player's character. 

Quartz: Quartzes are known to be brave and strong warriors. 
Ability Score Increase. Your Strength increases by 2 points. 
Warrior's Weapon. When you store a weapon in your gem, it becomes a +1 and magical. If the weapon normally has a +1, you can't use this bonus but can change the damage type of the weapon instead, such as from slashing to piercing or bludgeoning. 
Quartz Strength. You can choose to automatically succeed a Saving Throw. You can use this feature a number of times equal to your proficiency bonus. 

Peridot: Peridots are much smaller gems, often only near 3 ft tall, but are extremely intelligent and changes all of their Spellcasting bonuses from the Wisdom Stat to the Intelligence Stat. 
Ability Score Increase. Your Intelligence increases by 2 points. 
Ferrokinesis. You can lift metallic objects off the ground and move them as you wish. You can use the spell Telekinesis only on objects and entities made of metal. You can use this feature as an Action. 
Peridot's Understanding. You can interact with any magical or non-magical items. You can spend 1 Action to totally understand how an item works and what it is often used for, which includes weapons and constructs. 

Ruby: Rubies are small soldiers that overcome their physical vulnerabilities by grouping with another ruby or group of rubies and when needed, fusing with gems that do not only pertain to rubies. 
Ability Score Increase. Your Strength increases by 1 points as does your Constitution. 
Ruby's Flame. Each time you crit, you can put a extra 1d6 of fire damage onto the attack. This roll increases by 1d6 at 5th, 10th and 15th level. 
Determination. When a ruby has half of their max hitpoints or lower, it will have Advantage on all saving throws caused by enemies as long as at least 1 of the ruby's allies are within the same range of them that the enemy is. 

Sapphire: Sapphires are aristocratic and have an aptitude to divination magic. They're generally used by mages to help in construction of portals or to assist new students of magic schools or universities. 
Ability Score Increase. Your Intelligence increases by 2 points. 
Divination. If a sapphire uses a magic of the divination college, it can know a useful information about the object, event or creature that it's dealing with. 
Predictability. Once per day, the Sapphire can predict the movements or events of other creatures. It will have Advantage on all attacks and the enemy will have Disadvantage on saving throws against it until the end of the next turn of the sapphire. 

Lapis Lazuli: Lapis lazulis are generally terraformers and use the water of the planets they visit to mold mountains and cliffs. 
Ability Score Increase. Your Charisma increases by 2 points. 
Hydrokinesis. You learn the cantrip Shape Water and can cast Create or Destroy Water as 2nd level Spell a number of times equal to your proficiency bonus. Your swim speed is equal to your walking speed and you can walk on water. 
Water Shackles. When you make a melee, ranged or spell attack, you can use your Action and Reaction to create water shackles to restrain a medium enemy. At 5th, 11th, and 17th level, the size limit to restrain the enemy increases by one tier. The enemy must do a Strength Save or will be restrained until the Lapis Lazuli releases them. Each of the restrained enemy's turns, it can make a Strength Save to try and escape but will have Disadvantage doing so. You can do this a number of times equal to double of your proficiency bonus and your AC is the Strength Save DC. Each of your turns that you keep the enemy restrained, you lose 1 Action. 
Water Wings. As a Reaction, you can free a set of wings from your back. You gain a flying speed equal to your walking speed and you can retract your wings with no cost ay any time. 

You can fuse to another gem creature that is willing. You and the target must both be conscious to do so.

• All HP, maximum HP and temporary HP are added together.
• Modifiers of the highest level are added to modifiers of the lowest level. 
• The fusions both gain access to the equipment they both held in their inventories. 
• The fusion gains access to both of the classes' Spells or Traits. 
• The level of the fusion is the added level of both gems. 
• Size, weight and form are decided by players and, if needed, the Game Master. 
• HP Dice is doubled.
• If the fusion is attacked by force damage, it must succeed in a Constitution Saving Throw with a DC of 10 or the fusion ends immediately. 
• And finally, the fusion can be created for interpretation and fun or for combat.