DaYan Gem puzzles
The DaYan Gem family has 8 twisty puzzles. They were released one-by-one so we had to wait for them patiently to come out. They all have very good quality vinyl stickers, but the turning quality, solving experience and other characteristics are different. If you want to buy just one of them then I would probably recommend the DaYan Gem 3, because this moves the best and it doesn't jumble. If I had to rank them this would be my list: 3, 4, 2, 1, 7, 6, 8 and 5 but all of them makes a great collection piece.
The first four members of the family
DaYan Gem 1
This is an edge turning tetrakaidecahedron-shaped puzzle, a 14 sided truncated octahedron. At first sight it may feel cheap but after lubrication and setting the tension it moves relatively smooth.
The DaYan Gem 1 does jumble which means that with an invalid move one peace can go to a place where it shouldn't be. In this case a corner piece is sticking out. This is similar to the jumbling of the Helicopter cube. If you avoid this situation then it is not so hard to solve.
DaYan Gem 2
The DaYan Gem 2 has triangle (or more like hexagon) and square-shaped faces. It is turning really bad but with lubrication and setting the tension you can make it a little bit better. There's a triangle shaped piece which always gets stuck.
This puzzle jumbles between the corners and it can block. Try to avoid that.
DaYan Gem 3
This is a tetrakaidecahedron-shaped face turning puzzle and it has the best quality of the DaYan Gem family, it's worth buying it. It turns really nice, and the turning sound echoes inside the puzzle because it is hollow. The DaYan Gem 3 doesn't jumble however you can force a piece to the wrong place but this is not happening accidentally.
There's a limited blue-body version, only a 100 of these were made but it is also available in black, white, yellow and pink plastic.
DaYan Gem 4
The fourth DaYan Gem is the deep cut version of the third model. It looks the same as 3 and 7 but it doesn't turn around the square faces but it can be turned at the middle of the puzzle. It doesn't jumble and has a really good quality, that's why I put it on the second place in my must-have-list.
DaYan Gems 5, 6, 7, 8
DaYan Gem 5
DaYan Gem 6
The sixth gem has 30 faces and it's looking like a beast with its 6 large octahedron and 24 small faces. The most expensive member of the family doesn't jumble. Its quality is fair enough but some stickers might peel off.
DaYan Gem 7
I have mentioned already that the 3, 4 and 7 look the same. This one turns on the hexagonal and square faces, and it jumbles when a hexagonal face interacts with another hexagonal face.
DaYan Gem 8
The last model in our list has 4 hexagonal and and 4 triangle faces. It doesn't jumble but it feels a little cheap and catchy.