Help needed

Hello, I need some help with a trip to Tanzania. I would like to know about safe and reliable agencies, not luxurious ones, because that is not the idea. I am planning an ascent of Mount Kilimanjaro from April 9 to April 18, 2026.

On the way down, I would really love to get an authentic tanzanite. I am not sure if I want a pendant or a piece of jewelry. The important thing is to know that what I get is authentic, and I want to always carry it with me so that whenever I am asked about it, I can remember the wonderful moments from Tanzania. I would also like the jewelry to come with a certificate of authenticity or something similar to ensure it is genuine.

I would greatly appreciate recommendations for trustworthy trekking agencies and suggestions for places where I can buy tanzanite or tanzanite jewelry.