Text-Only Instructions

Various sites show how to fold this model. See, for instance,

Paper to be used: 3 squares of similar size; use large paper to practice with at first.
Thicker paper or thin cardstock is strongly recommended.
Note squares will also make nice, small models, but only use these when you are comfortable with the folding and assembly of these units.
Folding level: Beginner/Intermediate
Steps: 22
This model has many names, including Tashie's Jewel, crane's egg, fortune cookie and perhaps many more creative names in different languages.
The finished model is a closed, three-dimensional shape with 6 faces, 9 edges and 5 vertices, which makes it a type of convex hexahedron and also a triangular bipyramid.
All 6 faces are congruent (similar) and shaped as triangles.
4 of the sides come together in a sharp point, which could be considered as the top of the shape, while  the last 2 faces seem to form a flatter bottom area.
Being constructed using Sonobe units, the flaps and pockets will also cause the surface of each face of the model  to be divided into 2 parts.
This same shape can also be folded using strips of paper or triangular units.

If you are interested in finding out more about these and other  kinds of 3D shapes, you can go to the page below.

This modular creation has an unusual jewel-like appearance; hence the shape can often be found in jewelry items.

These models also look beautiful displayed in a large, flat bowl or see-through jar or vase, or use them as party favors or hanging decorations.

To use as a box, small objects can be added before the last module is inserted.

You will be folding 3 similar units to form your triangular hexahedron.
It is recommended that you fold all 3 pieces before attempting Phase 3, which will explain how to fit the pieces together to form the finished model.
If using two-sided origami paper, lay your paper with the patterned or colored side down before starting to fold.
NOTE: This phase describes how to fold the basic Sonobe unit. If you are able to achieve this without instructions, fold 3 Sonobe units and then go to Step 9.
Step 1
Place a square  down  with its edges to the left and right, top and bottom.
Step 2
Fold the top edge down to meet the bottom edge to form a horizontal center crease line.
Crease and unfold.
Step 3
Now fold the top and bottom edges in to meet the horizontal center crease line.
Crease and leave folded.
You will have a figure with an upper and a lower rectangular flap meeting each other along the horizontal center line.
Step 4
Now, fold the top left corner, all the layers, diagonally down to the right as far as it will go. It will line up with the bottom edge of the paper and form a triangle on the left side of the unit.
Crease well and leave folded.
Step 5
Repeat this fold with the bottom right corner of the rectangle.
There will now be 2 triangles that have formed next to each other, pointing in opposite directions.
The outline of the figure will be a more or less rectangular shape, but with points on each side.
Step 6
Unfold the 2 triangles so you have the rectangle again.
Step 7
Notice that you will now have short diagonal valley fold lines at the bottom left and top right corners of the rectangle.
These lines extend only halfway from the corners to the central slit of the rectangle.
Reverse the valley creases so they become mountain folds by folding the bottom left and top right corners inwards so they are hidden within the layers of the paper.
It should look as if a small corner is now missing at the left bottom and top right of the rectangle.
Step 8
Refold and tuck the large left triangle you created in Step 4 under the small corner just below it and then do the same with the large triangle on the right, tucking it in under the small top right corner just above it.
This will lock your Sonobe unit securely so it stays closed.
Important: Always start to fold your large corners in the same way; in this case, the top left and bottom right corners. If you make a modular model and one or more of the units are created with the opposite corners folded in, the units will not fit together.
You will now have a securely locked, long, skinny diamond shape, or to be more accurate, a parallelogram.
Keep the unit with its points at the left and right and with the smooth side facing the table for the explanation that follows:
Step 9
In order to use your Sonobe unit to make modular origami figures, it will help a lot if you can identify the main back and front  parts of the unit and familiarize yourself with its features.
Depending on which type of modular figure you want to make, you will fold your Sonobe unit slightly differently, so for the purpose of this short explanation, the parts of the units will first be described in general terms.
 (A) The Slits or Pockets
If you consider the surface of the module, which we will call the front, you will notice 2 diagonal folds with two loose flaps that face in opposite directions.
These folds  are actually openings, slits or pockets where the points of other modular units will be inserted.
Note that the face or central square of each unit will seem to have 4 diagonal openings, all facing in the same direction and arranged in a kind of pinwheel formation.
 You will always be using the 2 slits that are opposite from each other and that have a single layer of paper.
So, it is worthwhile checking that you can distinguish between the double-layered openings, which will not be used, and the single-layered slits which will be on opposite sides of each unit.
(B) The Central Square
Turn the unit over from left to right and place it so one of its long sides is facing you. The surface of the unit, which we will call the back, should now be smooth.
With the unit in this position, you will be able to identify the central square, with the left triangle  forming a point nearest you and the right triangle forming a point furthest away from you.
This orientation of the parallellogram is important and all your modules should have the central square and points folded in this way.
(C) The Points or Flaps
With the central square placed straight in relation to the edge of the table, you will have a triangular flap on the left, with its pointy end nearest you. On the right, there will be a similar flap, but this one will have its point furthest away from you.
Put in another way, the left triangle will seem to slope downwards from the left side of the central square while the right triangle will seem to slope upwards from the right side of the central square.
These points or flaps will be inserted into the slits or pockets of other similar units.
This completes the explanation of the basic Sonobe unit.
Three more steps are necessary to prepare the unit for using it to fold our triangular hexahedron.
Step 10
Place the unit down again, so it has a smooth surface. Position it so you have the central square with its bottom edge horizontally or lined up with the table.
You will have a triangle on the left of the square, sloping downwards and another on the right, sloping upwards.
Step 11
Fold the left corner straight over to the right and the right corner straight over to the left so the bases of the triangles meet each other diagonally across the square.
The folded triangles will thus meet each other perfectly and cover the central square.
Make sure that all 4 edges of your square are straight and really creased well at this point. Press extra hard since firm creases will make the assembly of the model much easier.
Step 12
Lastly, fold the bottom left corner of the square diagonally up to meet the top right corner and crease along the fold in order to accentuate the diagonal crease of each unit.
Gently unfold the last 2 steps and set aside.
Repeat steps 1 to 12 2 more times so you have 3 similarly shaped units to work with.
Make sure you follow the instructions for all the squares precisely since all units should be alike in order for the modular pieces to fit. In particular, the pockets and slits of all modules need to face in the same direction on each piece. If some of the units are folded with the slits and pockets facing in the opposite direction, the points of the other units will not fit.
The parallelograms should also be folded in the same way, corresponding to the description in Steps 9 to 11 above.
Step 13
First look at your folded Sonobe unit. It has a square with two flaps that seem to point in opposite directions. The square itself has a smooth surface on one side, but various pockets or slits have been created on the other side. These pockets are where you will be inserting the flaps of the units of the hexahedron.
The smooth sides of the squares will thus be hidden on the inside of the model while the points will fit into the pockets on the outside of the hexahedron.
Don't be afraid to use a fingernail to open the pockets. You should be able to figure out where the pockets are and how to slide the flaps of the new units into them once you start assembling the model.
Step 14
Start by placing one unit down with its flaps at the top and bottom. The square part of the model will lie flat while the flaps will point towards the ceiling.
The smooth side of the central square will be facing up, so make sure the side with the pockets is facing the table.
Step 15
Now take a second unit and place it at the right of unit 1, with its flaps out to the left and right.
Step 16
To connect the first 2 units, lift unit 1 slightly and insert the left point of unit 2 into the nearest pocket you will find at the back of the central square of unit 1.
  Slide it in all the way. The point will disappear and the first two units will be loosely joined by their sides.
Step 17
 Take the third unit and holding it with its flaps at the top and bottomm and coming from a point furthest away from you, insert its bottom point into the open pocket at the back of uni 2.
Slide it in all the way. The point will disappear and  all 3 units will be loosely joined by their sides.
After you have connected the 3 units you will have a loose structure that is still fairly flat on the table, with various points jutting out and standing at a 45 degree angle.
There will actually be 3 central squares connected along their sides and 4 pointy flaps on the outside of the central structure: both flaps of unit 1, the right flap of unit 2 and the top flap of unit 3.
It is now time to bring the different points together in order to create the hexahedron shape.
Keep in mind that as you start to insert flaps into pockets, your central squares will start to bend along the diagonal creases you have reinforced in Step 12 above.
Step 18
Locate the loose point of  unit 1 at the side furthest away from you and insert it into the unused pocket at the back of unit 3, which is just to its right.
Since this fold will let the left side of the hexahedron rise up a little, you may have to bend the point to get it into the pocket.
Put in another way, tilt unit 1 to the right and slide its loose point into the back of unit 3 in order to form a 90 degree corner, starting the process of forming a 3D shape.
The model so far should look like one corner of a cube.
It will look as if 2 walls of the 'cube' have formed at the back and on the left of the shape. There will also be 3 loose flaps as follows:
First, a flap at the back of the shape, belonging to unit 3,sticking up into the air;
 Second, a flap flat on the table on the right, belonging to unit 2; and
 Third, a flap pointing towards you, which belongs to unit 1 and is the flap we will be working with next.
Step 19
Locate the loose point of  unit 1 at the side nearest you and tilting the left wall of the figure, insert it into the unused pocket at the back of unit 2, which is just to its right.
This step will cause the walls of the 'cube' shape to be pressed nearer to each other, forming a sharp corner.
Don't be alarmed if it seems that your shape wants to crumple. Keep using the creases you have already created to form the outer edges of the shape. If it helps, you can gently pick up the model and lightly hold it in one hand while shaping it by pressing from the inside. since all the faces of the shape should bulge toward the outside.
Step 20
You will have a fairly uneven shape now, kind of like a hollow pouch.
Make sure the remaining two points are not on the inside of the model.
Step 21
Insert the point of unit 3, towards the left, into the remaining pocket of unit 1.
Step 22
Lastly, carefully slide the last point, belonging to uni  2, into the last pocket of unit 3, in order to close the modular figure completely.
Gently press the corners and sides into shape if necessary.
Congratulations! Your triangular hexahedron is finished.
Making origami accessible to visually impaired crafters through text instructions.
for non-commercial use only.
Compiled by Lindy van der Merwe, July 2023