# Crochet Hyperbolic Coral

Math was always my favorite class in school and in college. Now I found math beauty in crochet. This is hyperbolic coral!

Dr Daina Taimina, a professor of mathematics at Cornell University, discovered that the best way to make models of hyperbolic surfaces is using crochet.

Creating hyperbolic models using crochet is relatively simple: in each round, you add stitches at a constant rate. The more frequently stitches are added, the more quickly the model will ruffle up. You can use single crochet, half double, or double crochet as you choose (I was using double crochet).  You can experiment with different yarn and hook sizes to achieve different looks. You can work with a single strand of yarn or a combination of yarns worked together.

Materials: I was using crochet cotton threads size 10 and hook size 1.8 mm (for smaller corals) and crochet cotton threads size 3 and hook size 3.25 mm (for larger corals).

Abbreviations:
Ch – chain
DC – double crochet
HDC – half double crochet
SC – single crochet
Sl St – slip stitch

Notes:
– Work in both front and back loops;

– Work in spiral – do not join rounds;

– You don’t need to use stitch marker to keep track of where the rounds started – you will be adding stitches at a constant rate;

– Number of rounds depends on size of coral you desire (my samples have from 5 to 7 rounds).

Instructions

Model 1.

Ch 8, join with Sl St to form a ring.

Round 1. SC, 2 HDC, 16 DC in the ring, do not join the round.

Round 2 and all following Rounds: 2 DC in each St.

Last Round – finishing: When you have the coral as big as you want, make HDC in next 2 Sts, SC in next St, Sl St in next 2 Sts, fasten off.

Model 2. Brain coral.

Ch 8, join with Sl St to form a ring.

Round 1. SC, 2 HDC, 16 DC in the ring, do not join the round.

Round 2 and all following rounds: 3 DC in each St.

Last Round – finishing : When you have the coral as big as you want, make HDC in next 2 Sts, Sl St in next 2 Sts, fasten off.

Decorative edges:

Method 1:  After making last Sl St in the last Round:  *Ch 4, Sl St into the next St* – repeat from * to * to the end of the Round.

Method 2:  After making last SC in the last Round: **Ch 3, SC into the next St** – repeat from ** to ** to the end of the Round.

1. Roseanne Salyer
05/24/2016 / 3:14 pm

I have started doing Free Form crochet projects. These shapes will be great for me. I love all the different shapes I can get with simple stitches. Thank you for the patterns. I love the caterpillar.

2. Perriann McCoppin
05/26/2016 / 4:26 pm

Hi! I love these hyperbolic corals. I’m a retired high school math teacher and I get especially excited about the mathematics used in crochet. I loved using activities to teach concepts in class. Sure wish I’d have been more active in crochet at that time; I would have definitely used it in class. What fun! ANYWAY, I am thinking to try using the new Red Heart Scrubby yarn, Mary Maxim Scrub It yarn, or strips of nylon netting to make some of these corals as 3D dish scrubbers and washcloths. I know they will be great with the nylon netting because of its stiff texture. I’ve actually experimented with the constant stitch increase on nylon netting…once. It turned out pretty cool, but my niece wanted it so I didn’t get to try it out myself. Looking forward to trying your patterns on the yarns. Thanks for the post. I’m looking forward to checking out your other patterns, and recipes as well.

3. Kathy Fortney
06/02/2016 / 6:22 am

#BestIdeaEver — This is great idea