Jarosite is not used in jewelry as it is too brittle. The luster is also dull and it is usually a dark yellow or brown stone.

Rarity is relative. My experience and a quick perusal of mindat.org would suggest that jarosite is not very rare. (There are many hundreds of localities, and fine micro crystals can be easily purchased for a few bucks.) However, jarosite is indeed rare in large crystals or fine specimens of display quality.

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern JA---IT-. That is, eight letter words with 1st letter J and 2nd letter A and 6th letter I and 7th letter T. In alphabetical order, they are:

jarosite

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 5 words with the pattern J---SI--. That is, eight letter words with 1st letter J and 5th letter S and 6th letter I. In alphabetical order, they are:

jacksies

jarosite

jaunsing

jocosity

jonesing

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 3 words with the pattern J-R-S---. That is, eight letter words with 1st letter J and 3rd letter R and 5th letter S. In alphabetical order, they are:

jarosite

jurassic

juristic