I found this pattern on the net and I liked it so much I had to try and make it. At first glance it reminded me of wrought iron lattices on Tunisian windows we admired so much.
Round 1: Sc in 8th ch from hk, make a (3-chain) picot, ch 5, skip 3 and sc in next st. make a picot, ch 2 skip 1 and in the last st make 1 dc.
Round 2: ch1 sc1 over the dc you just made, then ch5, make a sc on the loop (chain) below, make a picot, chain 5 and sc 1 on the loop below.
Round 3: chain 5, sc in loop below, make a picot, chain another 5, sc in loop below, ch 2 and make a dc on top of the previous dc.
Round 4: repeat round 2
I liked it better vertically so that's how I used it for my necklace. I hung it on a chain and added a lovely skeleton key to it.