Lakhori bricks

Kos Minar, built with lakhori bricks hidden underneath lime mortar, along Grand Trunk Road at Taraori in Karnal district of Haryana, India.

Kos Minar, built with lakhori bricks, near the Tomb of Ali Mardan Khan at Lahore in present-day Pakistan.

Contemporary 9 × 4¼ × 2¾ inches bricks are similar in dimension to "Ghumma bricks" introduced by British raj in early 20th century to replace lakhorie bricks that were less than 3/4 in every dimension.

Lakhori bricks (also Badshahi bricks, Kakaiya bricks, Lakhauri bricks) are flat, thin, red burnt-clay bricks, originating from Lahore, Pakistan that became increasingly popular element of Mughal architecture during Shah Jahan, and remained so till early 20th century when lakhori bricks and similar Nanak Shahi bricks were replaced by the larger standard 9"x4"x3" bricks called ghumma bricks that were introduced by the colonial British India.^[1][2][3][4]

Several still surviving famous 17th to 19th century structures of Mughal India, characterized by jharokhas, jalis, fluted sandstone columns, ornamental gateways and grand cusped-arch entrances are made of lakhori bricks, including fort palaces (such as Red Fort), protective bastions and pavilions (as seen in Bawana Zail Fortess), havelis (such as Bagore-ki-Haveli, Chunnamal Haveli, Ghalib ki Haveli, Dharampura Haveli and Hemu's Haveli), temples and gurudwaras (such as in Maharaja Patiala's Bahadurgarh Fort), mosques and tombs (such as Mehram Serai, Teele Wali Masjid), water wells and baoli stepwells (such as Choro Ki Baoli), bridges (such as Mughal bridge at Karnal), Kos minar road-side milestones (such as at Palwal along Grand Trunk Road) and other notable structures.^{[5][6][7][8][9]}