Hadlakas Neiros Shabbos-Olive oil or wax?
Many of you I am sure have noticed that while most people light Shabbos candles using wax candles, some are particular to use olive oil. On the other hand, by Chanukah most of Jewry uses olive oil while only some use wax. Should olive oil be used even for Shabbos candles? Which is the better approach? In the Halacha below we will see a difference between the law and practical custom in terms of what one should choose for his Shabbos candles lighting.
What type of oil/candles should one use for lighting Shabbos candles?
All oils [and wax], other than those explicitly excluded by the Sages, are initially valid to be used for Shabbos candles.
Olive oil versus wax or other oils: Although all oils [and wax], other than those explicitly excluded by the Sages, are initially valid to be used for Shabbos candles, nevertheless it is a Mitzvah Min Hamuvchar to be scrupulous to use olive oil, just as is the law regarding the Chanukah candles. [Some Poskim however rule that if the wax candles light just as well as olive oil, then there is no need to use olive oil. Practically, many are accustomed to use specifically wax candles for Shabbos, while for Chanukah candles olive oil is used. The Chabad custom is to use specifically wax candles for Shabbos.]
Although it is a Mitzvah Min Hamuvchar to light Shabbos candles using specifically olive oil, nevertheless the widespread custom of Jewry, as well as the Chabad custom, is to use specifically wax candles.
If one is particular to light with olive oil, must they do so also when they are away from home?
 264/12; Michaber 264/6; Shabbos 23a
 Some write one is to light at least two candles from olive oil. [Siddur Arizal; Shulchan Hatahor 263; Likkutei Maharich; Or Tzaddikim 28/17] The Gr”a would light with olive oil [Maaseh Rav 112] and so was the widespread custom in Israel. [Ketzos Hashulchan 74 footnote 4]
The reason: The Sages praised the greatness of olive oil in various areas. [See Midrash Tanchuma Parshas Behaloscha]
The Segulos: Sefer Chassidim 272 writes that there was a certain individual who merited a long life simply due to his scrupulousness of using olive oil rather than wax, to light the Shabbos candles. [brought in Beir Heiytiv 264/4; Elya Raba 264/10; Likkutei Maharich] One who is careful to light with olive oil merits to have children that are Talmidei Chachamim, as the Torah Scholars in Israel are compared to olive oil in Sanhedrin 24a. [Machazik Bracha 264/2]
 M”B 264/23; Az Nidbaru 2/4
 Piskeiy Teshuvos 264/5; See Ketzos Hashulchan 74 footnote 4 that so is the custom of the Diaspora, however in Eretz Yisrael the old custom is to use olive oil, and so is to be done by those who move to Israel.
 The reason: Some write the reason for this is because there is no worry of “Michabeh and Maavir” by tilting wax candles [not placed in a bowl], and hence there is no fear of shaking the table that they are on. Likewise this is due to that today’s wax candles light just as well as oil. [Piskeiy Teshuvos ibid; see M”B ibid]
 Likkutei Sichos 21 382 [printed in Shulchan Menachem 2/40] “In the home of the Rebbe Rayatz I never witnessed, even one time, that they used olive oil for Shabbos and Yom Tov candles. Rather they used wax candles. However for the Chanukah candles, olive oil was used. I did not hear a reason behind this”; See also Likkutei Sichos 35 footnote 320 “It is a Mitzvah Min Hamuvchar to use olive oil for Shabbos candles. However “Puk Chazi Maiy Ama Dabar/Go see what the custom of Israel is”.”
 Piskeiy Teshuvos 264/5, based on Birchas Habayis 45/17
 The reason: As we assume she never accepted upon herself to light with olive oil in such circumstances.