1. E. Not to cause others to be jealous:

Not to cause others to be jealous:[1] It is forbidden for a man to beautify himself in order so he  appear attractive in the eyes of a married woman and cause her to be infatuated with him in her heart. Likewise, it is forbidden for one to praise the beauty of a married woman in front of other men as doing so can lead them to covet her.[2] [Seemingly, the same should apply to other objects of the person, that one should not show off his assets and belongings and cause others to be envious of him and covet his objects.]

Not to cause Gentiles to be jealous of a Jews Jewelry:[3] The Sages enacted that in commemoration for the destruction, upon a woman dressing herself with jewelry, she is not to wear all the types of jewelry that she usually wears and is rather to leave one out. [Thus, if she owns and wears a necklace, rings, earrings, and bracelet she is not to wear all of them at the same time.[4] Those that wear all of their jewelry, aside for transgressing this law, also cause jealousy amongst the gentiles.[5] On Shabbos and Yom Tov, some Poskim[6] rule it is permitted to wear all the available jewelry. Other Poskim[7] however rule it applies even on Shabbos and Yom Tov. Although the above ruling is recorded in the Poskim[8] without argument, practically, today the women are no longer accustomed to leave out a piece of jewelry even during the week.[9]]

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[1] Sefer Chassidim 99; Sefer Hayirah; Mishneh Halachos 7:143; Encyclopedia ibid p. 483-484 footnotes 295-297

[2] The reason: as the words Lo Sachmod can be read as Lo Sichameid, which means not to cause others to be jealous.

[3] Michaber 560:2; Bava Basra 60b

[4] See M”A 560:6

[5] Shlah 200a; M”B 560:8; Kaf Hachaim 560:20

[6] Mor Uketzia 560; Birkeiy Yosef 560:5; M”B 560:5

[7] Mor Uketzia 560; M”B 560:5 in Shaar Hatziyon 560:13

[8] M”B ibid; Aruch Hashulchan 560:6; Piskeiy Teshuvos 560:8

[9] See Shulchan Gavoa 560:5; Chayeh Adam 137:2; M”B in Biur Halacha 560:2 “Vichein Hiskinu”; Kaf Hachaim 560:18 and 21; Sefer Eretz Yisrael of Rav Tukechinsky 23