Diamond Heirloom Blanket

The Diamond Heirloom Blanket is a 20-square throw designed to be made slowly and kept for a long time. Each square grows from a center ring outward through 12 rounds, building a solid double crochet frame in the first four rounds before opening into a diamond-ridge lattice in rounds 5 through 11. The lattice widens symmetrically from the center of each side — one additional repeat per round — until the diamond fills the square completely. A final round of single crochet closes and frames each motif. The squares are joined with a visible single crochet ridge seam, a deliberate design choice: the raised seam catches light and gives the finished blanket structure and presence. A 5-round border finishes the edge — two rounds of single crochet, a double crochet mesh worked in two layered rounds, and a final round of single crochet. **Materials** Lion Brand 24/7 Cotton DK (100% mercerized cotton; 186 yd / 170 m per 100 g skein) — 10 skeins total (approx. 1,860 yards). Shown in Ecru and White. 3.5 mm (US F/5) hook, or size needed to obtain gauge. Tapestry needle, rustproof blocking pins, steam iron or spray bottle. **Gauge** Each finished square measures 10½ in (26.5 cm) after steam blocking. Gauge is important — block and measure your first square before continuing. **Finished size** Approx. 48 in × 58 in (122 cm × 147 cm) — a generous throw. **Techniques used** Double crochet, single crochet, slip stitch, chain spaces, front post stitches, corner shells, single crochet join, steam blocking. All rounds are worked on the right side; no turning between rounds. **A note on the diamond ridge** Beginning in Round 5, a ch-1, skip sequence introduces the central openwork. Each subsequent round adds one more repeat on either side, widening the diamond outward. The starting point shifts slightly each round — this is intentional, not an error. Trust the shift. **Pattern notes** Written in US crochet terms. Stitch counts given at the end of each round. Block all 20 squares before joining for the cleanest seams and most accurate finished size. Care: machine wash cold, gentle cycle; tumble dry low or lay flat. Cotton softens with use.