Lacy Rhombus in Filet Crochet
Lacy rhombus in the filet mesh  traditional decoration things, which were made using technique of filet. Since the rhombus is element of the mesh, we will not tell about the turning chains, the edge stitches and the initial row in the description of the pattern. Repeat (rapport) of the pattern  18 loops and 10 row. We offer for beginners both the description and chart for convenience crochet this pattern
1 row: * 1 double crochet, 1 chain * (filet mesh)  9 times;
2 row: * 1 chain, 1 double crochet *  3 times, 1 chain, 3 double crochet in space of the chain of the previous row, * 1 chain, 1 double crochet *  4 times;
3 row: * 1 double crochet, 1 chain *  3 times, 3 double crochet in space of the chain, 4 chains, 3 double crochet in space of the next chain of the previous row, 1 chain, * 1 double crochet, 1 chain *  2 times;
4 row: 1 chain, 1 double crochet, 1 chain, 3 double crochet in space of the chain, 3 chains, 1 single crochet in space of four chains of the previous row, 3 chains, 3 double crochet in space of the chain of the previous row, * 1 chain, 1 double crochet *  2 times;
5 row: 1 double crochet, 1 chain, 3 double crochet in space of the chain of the previous row, 3 chains, 3 single crochet in loop of the single crochet of the previous row and two chains near, 3 chains, 3 single crochet in space of the chain of the previous row, 1 chain;
6 row: 3 single crochet in space of chain of the previous row, 3 chains, 5 single crochet in loops of three single crochet of the previous row and two chains near, 3 chains, 3 single crochet in space of chain of the previous row;
7 row: 1 double crochet, 1 chain, 3 double crochet in space of three chains of the previous row, 3 chains, 3 single crochet in three central loops of five single crochet of the previous row, 3 chains, 1 double crochet in space of three chains of the previous row, 1 chain;
8 row: 1 chain, 1 double crochet, 1 chain, 3 double crochet in space of three chains of the previous row, 1 single crochet in central loop of three single crochet of the previous row, 3 chains, 3 double crochet in space of three chains of the previous row, * 1 chain, 1 double crochet *  2 times;
9 row: * 1 double crochet, 1 chain *  3 times, 3 double crochet in space of three chains of the previous row, 3 double crochet in next space of three chains, 1 chain, * 1 double crochet, 1 chain *  2 times;
10 row: * 1 chain, 1 double crochet * 3 times, 1 chain, 3 double crochet in space between two groups of three stitches of the previous row, * 1 chain, 1 double crochet * 4 times.
Then continue to crochet a filet mesh.
Crochet chart
Pattern Chart Symbols
Chain stitch (ch). 

Singls crochet (sc). 

Double crochet (dc). 
We recommend looking at:
How to Read Crochet Charts
Crochet Chart Symbols and Techniques