Lonsdaleite (named in honour of Kathleen Lonsdale), also called hexagonal diamond in reference to the crystal structure, is an allotrope of carbon with a hexagonal lattice, as opposed to the cubical lattice of conventional diamond.

藍絲黛爾石（英語： Lonsdaleite ）也譯做郎士德碳，又因晶體結構及特性稱作六方金剛石（英語： hexagonal diamond ）、六方碳。 藍絲黛爾石是一種 六方晶系 的 金剛石 ，屬於 碳同素異形體 的一種構形，咸信為 流星 上的 石墨 在墜入 地球 時所形成。

藍絲黛爾石 （英語： Lonsdaleite）也译做 郎士德碳，又因晶體結構及特性稱作 六方金剛石 （英語： hexagonal diamond）、 六方碳。 藍絲黛爾石是一種 六方晶系 的 金剛石，屬於 碳同素異形體 的一種構形，咸信為 流星 上的 石墨 在墜入 地球 時所形成。 撞擊時的巨大壓力及熱量改變石墨構形形成金剛石，卻又保留了石墨的平行 六邊形 晶格，並構成了立方的六方 晶格。 第一次鑑別出藍絲黛爾石是1967年在 美國 亞利桑那州 的 巴林杰隕石坑 [4]，從位在其中的「魔谷隕石」中 …

Physical Properties of Lonsdaleite : Cleavage: {???} Perfect : Color: Brownish black, Light brownish yellow. Density: 3.3 - 3.52, Average = 3.41 : Diaphaneity: Translucent to Opaque : Habit: Microscopic Crystals - Crystals visible only with microscopes. Hardness: 7-8 : Luster: Adamantine : Streak: brownish yellow : Optical Properties of Lonsdaleite

Color: Lonsdaleite is typically yellow or brown in color, which is different from the colorless appearance of regular diamond. Transparency: Like regular diamond, lonsdaleite is transparent, which means that it allows light to pass through it.

Transparent brownish-yellow, grayish. Named in honor of Dame Kathleen Lonsdale (nee Yardley) (28 January 1903, Newbridge, County Kildare, Ireland - 1 April 1971, London, England), crystallographer who established the structure of benzene by X-ray diffraction methods in 1929.

Lonsdaleite is also known as "hexagonal diamond." It is transparent brownish-yellow in color and has an index of refraction from 2.40 to 2.41, a specific gravity from 3.2 to 3.3, and a Mohs hardness of 7–8. The Mohs hardness of diamond is 10; the lower hardness of lonsdaleite is chiefly attributed to impurities and imperfections in the ...

Very fine-grained aggregates, forming cubes and cubo-octahedra, to 0.7 mm; in polycrystalline aggregates, mixed with diamond. Optical Properties: Transparent. Color: Grayish in crystals; also pale yellowish or brown in broken fragments. Luster: Adamantine. Optical Class: [Biaxial.] n = Slightly above 2.404.

Lonsdaleite was first identified in 1967 from the Canyon Diablo meteorite, where it occurs as microscopic crystals associated with diamond. General Information. Category: Mineral; Crystal system: Hexagonal; Crystal class: Dihexagonal dipyramidal (6/mmm) Color: Gray in crystals, pale yellowish to brown in broken fragments. Properties

Lonsdaleite (named in honour of Kathleen Lonsdale), also called hexagonal diamond in reference to the crystal structure, is an allotrope of carbon with a hexagonal lattice. In nature, it forms when meteorites containing graphite strike the Earth.