The tunnel continues upward on the other side, this is almost like a bubble in the middle of the tunnel.

The lock is fashioned and stylized like an ornate bearded dragon lizard, the keyhole to the lock is hidden within the design of the beard, and right above that is the face of the lizard. Within the the stylized face are 2 tiny holes where the flaring nostrils would be and around their edges are the tell tale signs of a powder dispensary. Opening the chest without the key trips the poisonous gas trap.

"Looks like some poisonous gas will come out when we try to open it without a key, so how we gonna do it?"

Petcan laughs. “Stand close everyone.” And proceeds to cast warding wind 

Once everyone is inside the wind, he’ll just open the chest. 

Besides the trap, the chest is locked.

Petcan rattles at the chest for a moment and gestures  to everyone in a frustrated manner, before gesturing in a lockpicking fashion

Bow takes out his thieves tools and starts working the lock:

20

Quote from Secretfool >>

Bow takes out his thieves tools and starts working the lock:

21

 Just in case that doesn't work, Z digs through his backpack and gets out a crowbar and a hand-axe, which he shows to the (deafened) party and offers to Brother Randall (best STR score).

Bow picks the lock triggering the poisonous gas trap, and Petcan's spell sweeps away the small cloud of poison before it can harm anyone.

Inside the chest is 267 cp, 3,863 sp, 541 gp, 92 pp in coins. Mixed in among the coins are 5 Obsidian, 9 Banded Agates, and 2 Rhodochrosites gemstones all worth 10 gp each. Also 4 Quartz, 9 Citrine, and 5 Jasper gemstones all worth 50 gp each. And finally, 8 Jade, 10 Pearls, 7 Amber, 6 Coral, and 6 Chrysoberyl (2 are transparent yellow-green and the other 4 are transparent pale green) gemstones all worth 100 gp each. Resting atop the pile within the chest is a lone gemstone the size of a peach pit, a Topaz worth 500 gp.

Mixed in among all these riches are a longsword, an ornate sack, 2 wands, and a helmet.

Nice hoard. Does Detect Magic identify any magic emanating from any of the items or gem in the hoard?

The longsword, ornate sack, 2 wands, and helmet detect as magical in nature. None of the gems are magical.

Zenodor shares this news once the magic wind stops and the group can talk again. 

"Magic items! What a valuable find. We should try to work out what magic they hold, but perhaps we best wait until we have returned to the surface".

OOC: Normally a character can identify a magic item over a short rest. How does this work with the customised 5min rest? Can we still identify over a (very) short rest, or does it take a full hour, so perhaps best left for later?

The only limitation I think they mention is on a long rest you only recover spell slots of 5th level or lower (in 1 hour), to recover spell slots of 6th and higher level you need an 8 hour rest.

I'm going to allow attuning over 5 minute short rests.

Randall:

     “Indeed, quite the haul.  Let me take a look at those wands,” asks Randall, considering if there is any religious iconography on them that might lend a clue to their purpose.

Religion:  18

Bow isn't interested in pieces of wood (wands) or a longsword. Do either the sack or the helmet have any markings that would imply anything about what they do?

Zenodor has little use for swords or helmets, so has a closer look at the wands

Quote from Brian_Avery >>

The only limitation I think they mention is on a long rest you only recover spell slots of 5th level or lower (in 1 hour), to recover spell slots of 6th and higher level you need an 8 hour rest.

I'm going to allow attuning over 5 minute short rests.

 I wasn't thinking of attuning (yet). More about identification. Unless someone has the spell "identify" prepared 5 times, it's the easiest way.

From Basic Rules, Chapter 14:

Using a Magic Item

A magic item’s description explains how the item works. Handling a magic item is enough to give a character a sense that something is extraordinary about the item. The identify spell is the fastest way to reveal an item’s properties. Alternatively, a character can focus on one magic item during a short rest, while being in physical contact with the item. At the end of the rest, the character learns the item’s properties, as well as how to use them. Potions are an exception; a little taste is enough to tell the taster what the potion does.

So, can we identify in a 5 minute short rest? Or does identify still follow longer timelines?

Petcan plays rock, paper, scissors with Zenodor for a wand and sets about identifying it over the course of a short rest. 

((Are we going to see a fight for the wands?:P))

Quote from nschrock >>

Petcan plays rock, paper, scissors with Zenodor for a wand and sets about identifying it over the course of a short rest. 

 Zenodor agrees, plays the game, and then takes whichever one of the wands he won/lost.