Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
Joan collects rocks. In her collection of rock samples, she had half as many gemstones as minerals yesterday. Today, she went on a rock collecting trip and found 6 more mineral samples. If she has 48 minerals now, how many gemstone samples does she have?

### Response:
 Jana kabla ya safari yake ya kukusanya mawe, alikuwa na madini 48 - 6 = <<48-6=42>>42.
Ana (42 / 2) 21 sampuli za vito.