Vault of Amber Stasis

You create a storage medium out of valuable gemstones (or solid amber) containing a given collection of non-living materials. The contents are held in stasis and will not age, weather or rot. Magical effects caused by items are disabled while they are inside, though standard rules for Detect Magic and similar spells can locate them as normal.

You place the four smaller gemstones in a rectangular shape on the ground, surrounding any items you wish the vault to contain. Using the largest gemstone as a focus, you spend the casting time tracing appropriate sigils, drawing a magical connection from each corner gem to the focus, speaking the verbal aspects of the spell and finishing with any command word you choose. Once the casting is complete, the corner gems and any items completely within the spell's area of effect vanish to be contained within the focus gem - this is now a "vault".

A given vault has a weight capacity up to the worth of the focus gem in lb, e.g. a 100gp vault gem may hold up to 100lb worth of items. Additionally, the collective size of the contents must fit within the volume of a three-dimensional box shape, the floorspace of which is determined by the arrangement of the smaller gemstones upon its creation; the maximum total volume of this cuboid is determined by the level of spell that created it, which itself determines the cuboid's height. This maximum volume is equal to 10ft³ and increases by an additional 5ft³ for every level above 3rd. See the table below for reference. Casting this spell as a ritual is equivalent to casting at 3rd level.

The resulting vault weighs as much as the combined weight of the five gemstones, no matter the contents. If the gem is closely inspected, the contents can be seen within as though miniaturised, provided the gem itself is translucent.

If the command word is spoken using an action or bonus action by the caster, or any other creatures the caster allows, the vault is "opened" - the four anchoring gems and all items placed within immediately reappear in their original configuration within the nearest available space to the larger gemstone; the speaker may mentally choose a specific space to use, if multiple spaces are available, but the distance between any of the smaller gemstones and the larger gemstone cannot exceed 30ft in length and each must be within line of sight to the larger.

If no space is available when the command word is used, the vault is dispelled or the gem itself is shattered by other means, the vault is "broken" - the four anchoring gems and all items placed within burst from a point centered on the large gemstone; any creatures within a 5ft radius are displaced to the nearest available space and must succeed on a Dexterity saving throw of DC 15, or take force damage equivalent to one tenth the maximum capacity of the vault (rounded down). If the spilled contents would occupy more than the available surrounding space, some of these items are, at random or as determined by the GM, are scattered into the Astral Plane or a similar other space also determined by the GM.

A vault gem created by this spell has an AC of 17 plus the spell's level, with one hit point. It cannot be targeted by any spell that ignores AC (such as the Magic Missile spell) and is immune to damage from non-magical weapons; it is also immune to any damage not dealt directly to it, such as if it is carried by a creature hit with an area-of-effect spell (such as the Fireball or Cone of Cold spells) and any effects that require a saving throw are automatically succeeded unless the DC is equal to or higher than its AC.