It's Definitely a Little Gem!
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Dayan Gem X |
Yes, it's twisty time again! Don't run away - this one is really good and is
actually solvable with a intuition alone and doesn't need any fancy algorithms
or even making up any commutators. This Dayan Gem X is a fabulous little gem of
a puzzle that can be scrambled and solved as a number of different challenges.
I would love to show you a photo of all of the Dayan gems but I have a bit of
an organisation issue:
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The gems are somewhere in there! I can see a couple at the back but
the thought of getting them out fills me with a sense of dread
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Gem 1 |
The Dayan Gem series are a fabulous bunch of puzzles and this is the 9th to be
produced - I have no idea what happened to the Gem 9 but I do hope that it
will be coming. The Gem 1 (which I reviewed
here
way back in 2012) and Gem X look identical as truncated octahedra but they
move differently. The whole point of all of this series is that they are
interesting geometries and very interesting ways of moving.
SuperAntonioVivaldi has made a fabulous
summary video about
the series). The
original Gem 1
was a pure edge turner and had a similar solve process to a
Curvy Copter. It was a fabulous challenge that mostly solved by intuition including the
jumbling, double jumbling and shape shifting. I adored it...especially seeing
as it didn't need a lot of fancy algorithms. Other Dayan Gems had similar
truncated shapes and had face turning, deep and superficial cut face turning
and even mixed edge and face turning. They were wonderful challenges that
varied from easy intuition to mind-bogglingly difficult (especially for a bear
of little brain like me). Every time one has come out I have been unable to
resist adding it to my collection and frightened of them to varying degrees.
Of course, when I saw the Gem X come out I couldn't resist it and for once did
not hold off scrambling and playing. As a general rule for you twisty novices
or twisty-shy puzzlers, you should definitely embrace the edge turning
puzzles. In my still extremely popular
Twisty advice for beginners
post and the follow up
extension post I expounded on the delights of the edge turners. The addition of
jumbling to a puzzle (with or without blocking) is so much fun and once you
have got your head around the concept it really makes for extra
interest.
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One edge and one face turn
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So what does the Gem X add? First of all it turns on the same edges as the Gem
1 (see the purple and yellow edge is turned in the picture) and on top of that
the square faces (of which there are six) also rotate (note the top left
yellow face is turned. The end result of this is that we have 3 or even 4
puzzle challenges. Firstly I went for a face-turn only scramble and solve
which, despite being extremely easy, was a lovely little challenge as a warm
up for the more difficult puzzle scrambles.
After the face-turn only solve then, of course, there is a I went back to an
edge only solve just like the Gem 1. It had been 10 years since I touched the
original Gem and I had no recollection of the solve process at all. But
keeping in mind what happens with the curvy copter, it is perfectly doable
with just some intuition and thought.
After that then there is a mixed scramble of edges and faces but no jumbling
and then attempting to solve that with only edge and face turns whilst
avoiding jumbling in the solve (a jumble move has a very specific effect on
the piece positions). Finally there is a full scramble with jumbling, double
jumbling, and finished with shape shifting - GULP!
First of all, the face turning challenge:
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Square faces only scrambled
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The effect of face turning is to mix up the bicoloured edges and move them all
over the puzzle whilst keeping the square faces intact. The solution to this
challenge is pretty simple. It is effectively an octahedral version of the Dino
cube and needs nothing more than my old favourite "up, up, down, down" sequence
to move all those edges into place one at a time until the puzzle is left with a
single 3 cycle which is also solved with that simple sequence. Stunningly easy
and a perfect start to boost your confidence.
Next up the original edge (Dayan Gem 1) scramble. Like all edge turners the
moving pieces remain in orbits and can be scrambled and solved logically just
by moving the pieces within their orbits until you have 3 remaining to move
into place and they solve with a simple intuitive 3-cycle. This, non-jumbling
scramble was my second method of scrambling and solving. It is not difficult
but it IS great fun. Then of course, once you have gained a little confidence
then it's time for a jumble - this involves partial turns of adjacent edges
and once lined up properly the edges can be rotated with shape shifting and
pulling pieces out of their set orbits to add another facet to the challenge
posed by this puzzle. The jumbling can be a double jumble which works like
this and leaves the puzzle in the correct shape:
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Two partial edge turns
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Then turn the central edge
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End result 2 edges swapped
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Performing an edges only scramble with double jumbling leads to a nice
challenge - it looks much more scrambled than the face only scramble but it
quickly becomes apparent that on the hexagonal faces 3 of the pieces are all
in the correct place.
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Edges only turned with double jumbles
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Step one reveals it not to be too tough
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The process of solving this puzzle is identical to the Gem 1 and if you have
not bought that then there is no need to. It can be shapeshifted by single
jumbling but I saved this for later.
One quirk of the double jumble solve is that occasionally it all solves
leaving one or occasionally more edges flipped:
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This is easy to fix if you remember the same thing on the Curvy copter
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The reason for this is that the double jumbling can be done from 2 set up
directions and therefore the solution is to redo the double jumbling twice.
Extra fun for you.
Next up was a combined edge and face scramble that DID NOT utilise jumbling. Why bother with this? Because the next challenge is to solve the puzzle without using jumbling. It is not an easy challenge. The edge turned pieces are no longer within their orbits because the face turns disrupts the orbits. But, having scrambled it without jumbling I decided to attempt to solve it without jumbling:
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It looks like any other non jumbled scramble |
The difference here is that everything is scrambled and no simple turns will suddenly solve half the face pieces. I picked a hexagonal face and built it using a combination of face turns and edge turns. After that I basically worked my way up the puzzle in an almost layer by layer fashion adding pieces as I found them. I did not memories the colour scheme and had to work out which faces went where on the fly. Occasionally I would realise that I had placed pieces wrongly and did not realise it until I had 2 identical coloured faces adjacent to each other or reached a point where there was no bicoloured piece that would fit in the required space. This led to me rearranging hexagonal edges into different arrangements until I found a colour setup that was possible. I never got too far into it before realising my mistake (you could just memorise the colour scheme and avoid my pitfall). Once the colour scheme has been fathomed, then it, again, is mostly intuitively combining of pieces and working my way up layer by layer. Once I was above the equator line it began to get tougher. There was less room to move. Despite this there is a fabulous fun process that is STILL INTUITIVE! Or so I thought...
I solved the puzzle in this way a couple of times and was brimming with confidence until I hit an awkward moment:
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Ooh! That shouldn't have happened. |
I had to undo part of the top of the puzzle and reorganise it with one of the square faces turned through 90º. We had a parity caused by the fact that all the pieces on the square faces can be moved and if one of them is reassembled with the interior rotated then it is reflected in the exterior of the puzzle. I was scratching my head over that one for quite a few hours! All part of the fun.
Finally, we also have the ability to shapeshift by not pairing up the jumbles
(i.e. single jumbles) which leads to a fearsome looking scramble:
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Single unpaired jumble
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Full face and edge scramble with ALL the jumbling
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It looks horrific but having done the interim non-jumbling solves then it
isn't too awkward to solve. The return to regular smooth shape just requires a
bit of fiddling about until you learn how to line the gaps and the sticky-out
bits properly and then twist them into each other. It is very satisfying to
return it to proper truncated octahedral shape.
Having done that then the remaining solution proceeds just as I had with the combined scramble above. Mostly intuition is needed at the beginning and then towards the latter half it became obvious that I needed to use double jumbles to move pieces about as well as intuitive combinations of edge and face moves which rotate pieces into place. As long as you know what the double jumble does then it is fun
to use it. The final process for this big scramble involves sometimes long complex setup moves which move the 2 pieces to be exchanged into the correct positions with respect to each other, performing the double jumble and then undoing those setup moves. Because I have the memory of a dementing goldfish, I had to write down a list of my setup moves so that I could undo them without mucking up all my hard work.
The Dayan gem X is a fitting new member of the Gem family. If you are a collector then it is an essential purchase. If you are a twisty puzzler then it is an essential purchase. More importantly, for those of you who are just occasional twisty puzzlers and frightened of the more complex puzzles then this is definitely one to add to your collection and you can safely scramble and solve it in any of 5 different ways and have great fun playing and solving intuitively. Go for it - you won't be disappointed.