Hello Eileen and welcome to the group.
Determining the value of an object is very hard to do in a discussion group like this in my opinion. Not everything is equal in African art, there is a wide range of quality and a wide range of places to market your object through depending on its perceived quality. People in this group can give you opinions or point you to places with similar objects to compare prices of these objects. Groups like this can be helpful in pointing you in directions for research and giving people opinions on objects they present
for comments, but the determination of value is a multi-layered and complicated thing.
First you have to do a little research, which is what you are doing by asking your question to the group, and it is a good start.
As Lee stated, the first thing you want to do is to correctly identify your object. As he suggested, you might wish to post photos of your object to the group if you want to seek opinions on this, and opinions on the style of the object and so on.
People from the group can give you their opinions of the object based on their own personal knowledge and experiences, and can provide you with links to online
resources or to books for you to look at if you wish to research further on your own. You will need to take these opinions and determine for yourself the next step you wish to take with your object.
Some Nimbas, like the one on my website that belongs to another collector, are very large and shipping can be problematic and expensive. You also have to consider how you want to sell it, and what your options are for selling it. If you are in a larger metropolitan market your chances of selling it locally or consigning it through a local dealer are much better than if you are in a rural area. Often times dealers will consign objects
for people for a commission. If you take the object to an auction house, you will usually pay a commission to an auction house to sell the object as well. IT can be expensive for you to ship your object to an auction house and not be guaranteed that it will sell. If it doesnt sell, then you are responsible for getting it back to you. The same can be true if you find a dealer to consign it, I guess it comes down to where you live and how large the object is.
You stated that I know it is authentic because the person who gave it to you used to buy for museums and has many important pieces of art as well as African art. Just this fact alone does not automatically determine
authenticity. Authenticity to some people is different than it is to others. An analysis of stylistic qualities, signs of wear and history will come into play when determining authenticity. Authenticity can be a complex thing to determine, and engaging a specialist may be necessary.
I think the first step for you to take would be to post a photo or 2 of the object to the group so people can give you opinions on the style of the object and give you their opinions on the plausible authenticity of the object as well. Maybe people can give you their thoughts on the best way to sell the object.
Based on that outcome, in my opinion and in your circumstance it might be best to contact a good auction house that has a decent reputation for selling collections of Tribal/Ethnographic art and the like. They usually have in house ethnographic specialists who will work with you to determine possible market value for your object(s) and help to put together a course of action and let you know what might be able to expect. Either that, or you may want to seek out a local dealer who has an established audience for African art to show the object to and see if they might consider consigning it for you. eBay may also be a good outlet for you to sell the object through, and depending on your comfort level you may need to contact a local company that does consignments and lists things for you because they handle
everything from the photos to the shipping.
Skinner auction house in Boston (http://www.skinnerinc.com/) is an example of an auction house that comes to my mind, and you might also try someone like Arte Primivito in New York .
Both auction houses have proven to bring in good prices on some nice objects.
The Art Fact website has a pretty comprehensive list of auction galleries on it and is linked
below. When you click on a link for an auction house it will tell you more about it and what kind of objects it specializes in.
Hope that helps some,
years ago I received a Congo Nimba mask from a freind and noted
collector who also gave me some other pieces of African art.I know it
is authentic because this man used to buy for museums and has many
important pieces of art as well as african art.I love the piece but
because of it`s size there is no where to display it in my home and it
has been in my cellar for 10 years now and I do not see any reason to
keep it any longer I am thinking of selling it and would like to know
what may be a fair price to sell it for.as I could use the money
towards my daughter`s college educaton next year.