Here is a step-by-step crochet tutorial for making the square shown in your image.
This design is called a twisted two-color block square — made from 4 triangle pieces joined while working.

🧵 DETAILED CROCHET PATTERN (Step-by-Step)

(US crochet terms)

🌿 PART 1 — MAKE 1 TRIANGLE

You will make 4 triangles total:
• 2 green
• 2 white

Each triangle is made from the center outward, like a pie slice.

🔺 Triangle Pattern (make 4)

Row 0 (foundation):

Ch 4, sl st to form ring.

Row 1:

Ch 3 (counts as dc)
5 dc into ring → 6 dc total
Turn.

Stitch count: 6

Row 2:

Ch 3
Inc: dc in same stitch
dc in next 4 stitches
Inc: 2 dc in last stitch
Turn.

Stitch count: 8

Row 3:

Ch 3
Inc: dc in same stitch
dc in next 6 stitches
Inc: dc + dc in last stitch
Turn.

Stitch count: 10

Row 4:

Ch 3
Inc
dc in next 8 stitches
Inc
Turn.

Stitch count: 12

Row 5:

Ch 3
Inc
dc across
Inc
Turn.

Stitch count: 14

Row 6:

Same as before.

Stitch count: 16

Cut yarn.
You should have a triangle with a long straight side and a pointed tip.

🧵 PART 2 — MAKE COLOR SETS

Make:
✔ 2 green triangles
✔ 2 white triangles

✨ PART 3 — ASSEMBLE THE 4 TRIANGLES

This is the important part to get the twisted shape.

Lay them like this:

Green     White
White     Green

But rotate each triangle slightly so the long edge sits diagonally.

This creates the “pinwheel twist” effect from the photo.

🔗 PART 4 — JOIN TRIANGLES (very detailed)

You will join along the long sides.

Use whip stitch OR single crochet.

Steps:

Join top green ➝ top-right white
Join top-right white ➝ bottom-right green
Join bottom-right green ➝ bottom-left white
Join bottom-left white ➝ top green

Now the center will look like a twisted pinwheel shape.

🟩 PART 5 — SQUARE BORDER (makes shape perfect)

Work around the whole piece.

Attach yarn (I recommend green):

Round 1 (evening round):

Do this slowly:

Work 1 dc in each stitch across straight edges
When you reach a point where 2 triangles meet, insert hook into BOTH triangle edges
When you reach a corner:
(dc, ch 2, dc)
Continue around
Sl st to join

Your square now becomes perfectly sharp and even, like the finished photo.

🪢 PART 6 — OPTIONAL OUTER ROUND (if you want a cleaner edge)

Ch 1
Work sc in each stitch
(sc, ch 2, sc) in each corner
Join

Now you have a professional-looking finished block.

🧶 JOINING MANY SQUARES (like the blanket in the right photo)

Arrange each square with alternating rotations:

A B A B
B A B A
A B A B
B A B A

Join with:

slip stitch join (flat)
or single crochet join (raised)
or whip stitch (nearly invisible)

This will create the exact repeating geometric pattern shown in the image.

Beautiful Crochet Granny Square