One of the categories of Mukseh discussed by the Halachic authorities in the context of the laws of Shabbat is "Mukseh Mahamat Hisaron Kis," which refers to delicate items which are generally not handled when they are not being used for their primary function. The Shulhan Aruch (Orah Haim 308:1) gives the example of knives that are used for professional purposes, such as a Shohet’s knife, a tanner’s knife, barber shears, and a Mohel’s knife. As these knives are very delicate, their owners ensure not to touch them when they are not being used for their designated purpose. Halacha therefore regards these knives as Mukseh, and they may not be moved on Shabbat for any reason, even for a permissible purpose, and even to protect them from the rain, sun, etc.
However, Hacham Ovadia Yosef (Hazon Ovadia, p. 90) makes a very important distinction with regard to this law of "Mukseh Mahamat Hisaron Kis." He notes that all the examples given in the Shulhan Aruch involve items whose primary function is an act that is forbidden on Shabbat, such as slaughtering and haircutting. Hacham Ovadia thus rules that a delicate item is forbidden to be moved on Shabbat only if its primary purpose is forbidden on Shabbat. Common examples would be electronic devices and games. Since these are expensive items that are generally handled only when they are used for their primary function, and that primary function is forbidden on Shabbat, they may not be handled for any reason. Another, lesser-known example, as noted by several Halachic authorities, is important documents, such as receipts, stamps, contracts and other commercial documents. As one is not allowed to read such material on Shabbat, the primary function of these documents is something forbidden on Shabbat, and because of their importance, they are generally kept in a safe place and not handled. Therefore, they fall under the category of "Mukseh Mahamat Hisaron Kis" and may not be moved on Shabbat. This is the ruling of Hacham Bension Abba Shaul (Israel, 1923-1998), the Menuhat Ahaba (Rabbi Moshe Halevi, Israel, 1961-2001), and the Shemirat Shabbat Ke’hilchatah (Rabbi Yehoshua Neubert, contemporary).
However, when it comes to expensive items whose primary function does not entail an act that is forbidden on Shabbat, these objects are not considered Mukseh on Shabbat. Hacham Ovadia gives the example of a picture that is framed and hung on a wall at a designated spot in the home. Even though the picture is permanently hung on the wall and not generally handled, it is not considered Mukseh because it is not designated for a purpose that is forbidden on Shabbat. Hacham Bension Abba Shaul disagreed with the ruling, and claimed that an item with a fixed place is considered Mukseh regardless of whether its primary function is forbidden on Shabbat. Hacham Ovadia, however, rules that an object is not considered "Mukseh Mahamat Hisaron Kis" unless its primary purpose involves an act that is forbidden on Shabbat.
Other examples would include rings, other jewelry, and ornamental articles such as vases. Even though these are all delicate items which are not commonly handled, they are not Mukseh on Shabbat. This would apply as well to a decorative Menorah, such as a silver Menorah, which is displayed somewhere in the home. The primary purpose of such a Menorah is not to be lit, but rather as an ornament (even if it is used for lighting on Hanukah). Therefore, its primary function is something that is permissible on Shabbat, and it is not Mukseh. Of course, if it was lit when Shabbat began, it may not be handled during Shabbat. But otherwise, an ornamental Menorah may be moved and is not considered Mukseh.
Summary: It is forbidden to move a delicate, expensive item on Shabbat whose primary purpose involves something that is forbidden on Shabbat. This would include a Shohet’s knife, barber shears, electronic devices, and important documents. Expensive items whose primary purpose does not involve an act forbidden on Shabbat, may be handled on Shabbat. These include jewelry, ornamental vases and Menorah, and framed pictures hanging on a wall.
