Why a museum about one gemstone
Tanzanite is mined in a single place on the planet: the Mererani hills south of Arusha, within sight of Kilimanjaro. Arusha City Council describes the city as the main market for tanzanite from those mines and records that it has been the trading centre for the stone for many years. A museum explaining where it comes from is therefore a reasonable thing for this city to have, and this is the one.
It sits in the centre of town and covers the geology of the deposit, the history of the discovery, how the rough is cut and graded, and how mining at Mererani works. There is a small display of specimens and of the grading scale, which is the part that is most useful to anyone who is thinking of buying.
What is not published about it
No Tanzanian government body publishes a description of this museum. Arusha City Council’s tourism account names three heritage sites in the city and this is not among them; it is not a centre of the National Museum of Tanzania. It is a private museum attached to a business in the stone, and it should be read that way: informative, and not disinterested.
That combination is common in single-commodity museums everywhere and does not make the geology wrong. It does mean the visit runs towards a counter, and that the grading information you are shown is the grading information a seller wants you to have.
The reason to go before you shop, not after
Tanzanite is the single easiest thing in northern Tanzania to buy badly. Certification, treatment, synthetic substitutes and grading language are all working against a visitor who has had half an hour to learn about them. Spending an hour on the subject in a room with labelled specimens, before anybody is quoting you anything, is the cheapest protection available.
The tanzanite guide covers certification and the specific traps, and it is the necessary companion to any visit here. Note that tanzanite is sold in Moshi as well as Arusha, with exactly the same questions attached.
Common questions
Is it a government museum?
No. It is a private museum and no Tanzanian authority publishes a description of it. The National Museum of Tanzania’s Arusha centres are the Arusha Declaration Museum and the natural history museum.
Where does tanzanite actually come from?
The Mererani mines south of Arusha, the only source anywhere. Arusha City Council states this directly and describes the city as the main market for the stone.
Is it a good place to buy?
That is not a question this page answers. Read the tanzanite guide on certification first, wherever you eventually buy.