Since we don't see this daggers very often I will post this one which recently ended by ebay for sharing and discussion:
http://www.ebay.com/itm/Tlingit-Dagg...#ht_101wt_1153
Here the description from the seller for later reference:
Athabascan Tlingit 15" Dagger from the WH Newton Collection taken in trade from one of his posts along the Upper Tanana River Basin between 1885-1905. Documentation of his early co-existence and trade with the Tlingit is found through U of Alaska's Archives/ Historical Chronicles/Fairbanks/Tanana Trading Post/William H. Newton. This dagger has been preserved as part of his collection for 125 years. The turquoise patina is not indicative of joinery or serious corruption in the dagger, but a reflects a seepage of moisture during storage. After a 25 year sojourn in Alaska's interior as a trader (the Tlingit were still semi-nomadic when Newton established 'posts' along their established migratory paths in the Upper Tanana River Basin area in the Northwest Territories).
And here some of the pictures.