The net of the jewelry box can be drawn as follows:
```
+------+ +------+
/ | / | / | / |
/ | / | / | / |
+------+ / | +------+ / |
| | |/ | | | |/ |
| +------+ | +------+
| / | | | / | |
| / | | | / | |
| / +----+ | / +----+
```
The dimensions of the horizontal rectangle are 18 in x 8 in and the dimensions of the vertical rectangle are 6 in x 9 in.
To find the surface area of the box, we need to calculate the area of each face and sum them up. From the net, we see that the box has six faces, each of which is a rectangle.
The front face has an area of 18 in x 6 in = 108 in²
The back face has the same dimensions as the front face, so its area is also 108 in².
The top and bottom faces have areas of 8 in x 9 in = 72 in² (2 of these).
The left and right faces have areas of 18 in x 9 in = 162 in² (2 of these).
Adding up all the areas, we get:
108 in² + 108 in² + 72 in² + 72 in² + 162 in² + 162 in² = 684 in²
Therefore, the surface area of the jewelry box is 684 square inches.