Streak (mineralogy)

For other uses, see Streak.
Streak plates with pyrite (left) and rhodochrosite (right)

The streak of a mineral is the color of the powder produced when it is dragged across an unweathered surface. Unlike the apparent color of a mineral, which for most minerals can vary considerably, the trail of finely ground powder generally has a more consistent characteristic color, and is thus an important diagnostic tool in mineral identification. If no streak seems to be made, the mineral's streak is said to be white or colorless. Streak is particularly important as a diagnostic for opaque and colored materials. It is less useful for silicate minerals, most of which have a white streak or are too hard to powder easily.

The apparent color of a mineral can vary widely because of trace impurities or a disturbed macroscopic crystal structure. Small amounts of an impurity that strongly absorbs a particular wavelength can radically change the wavelengths of light that are reflected by the specimen, and thus change the apparent color. However, when the specimen is dragged to produce a streak, it is broken into randomly oriented microscopic crystals, and small impurities do not greatly affect the absorption of light.

The surface across which the mineral is dragged is called a "streak plate", and is generally made of unglazed porcelain tile. In the absence of a streak plate, the unglazed underside of a porcelain bowl or vase or the back of a glazed tile will work. Sometimes a streak is more easily or accurately described by comparing it with the "streak" made by another streak plate.

Because the trail left behind results from the mineral being crushed into powder, a streak can only be made of minerals softer than the streak plate, around 7 on the Mohs scale of mineral hardness. For harder minerals, the color of the powder can be determined by filing or crushing a small sample, which is then usually rubbed on a streak plate. Most minerals that are harder have an unhelpful white streak.

Some minerals leave a streak similar to their natural color, such as cinnabar, lazurite and native gold. Other minerals leave surprising colors, such as fluorite, which always has a white streak, although it can appear in purple, blue, yellow, or green crystals. Hematite, which is black in appearance, leaves a red streak which accounts for its name, which comes from the Greek word "haima", meaning "blood." Galena, which can be similar in appearance to hematite, is easily distinguished by its gray streak.

References

  • Bishop, A.C.; Woolley, A.R.; Hamilton, W.R. (1999). Cambridge Guide to Minerals, Rocks and Fossils (2nd ed.). Cambridge: Cambridge University Press. pp. 12–13. ISBN 9780521778817.
  • Holden, Martin (1991). The Encyclopedia of Gemstones and Minerals. New York: Facts on File. p. 251. ISBN 1-56799-949-2.
  • Schumann, Walter (1992). Minerals of the World. New York: Sterling Publishing. pp. 18–16. ISBN 0-00-219909-2.

Read other articles:

Situs Tondowongso

Artikel ini tidak memiliki referensi atau sumber tepercaya sehingga isinya tidak bisa dipastikan. Tolong bantu perbaiki artikel ini dengan menambahkan referensi yang layak. Tulisan tanpa sumber dapat dipertanyakan dan dihapus sewaktu-waktu.Cari sumber: Situs Tondowongso – berita · surat kabar · buku · cendekiawan · JSTOR Komplek Candi Tondowongso merupakan situs temuan purbakala yang ditemukan pada awal tahun 2007 di Dusun Tondowongso, Desa Gayam, Keca...

 

 

Daftar stasiun radio di Jambi

Berikut ini adalah daftar stasiun radio di provinsi Jambi. Untuk Wilayah Jambi, Sungai Penuh dan sekitarnya Logo Frekuensi Nama Jaringan FM 87,70 Radio Bernama Independen FM 88,50 RRI Jambi Pro 1 RRI Pro 1 FM 90,90 RRI Jambi Pro 2 RRI Pro 2 FM 94,40 RRI Jambi Pro 3 RRI Pro 3 FM 95,20 Radio Eldity Independen FM 96,00 Radio Manggis Independen FM 98,40 Radio DIAZ KBR FM 99,20 RRI Jambi Pro 4 RRI Pro 4 FM 102,70 Radio Nur Independen FM 104,30 D Radio Jambi Independen, JambiTV FM 105,10 Radio Sala...

 

 

Chumash people

Native American tribe of California Not to be confused with the Chuvash people. ChumashHistorical Chumash villagesTotal population2,000[1]–5,000[2]Regions with significant populations  United States  ∟ California LanguagesEnglish • Spanish • formerly Chumashan languagesReligionTraditional tribal religion,ChristianityRelated ethnic groupsBarbareño, Ventureño,Ineseño, Purisimeño, Obispeño[3] The Chumash are a Native A...

Crisis actor

Individual who portrays a disaster victim Crisis Actors redirects here. For the Lemon Demon song, see Spirit Phone. Emergency medical technicians from the 96th Medical Group move an airman pretending to be wounded toward safety during an active shooter exercise at Eglin Air Force Base in Florida in 2014. A crisis actor (aka actor-patient or actor victim) is a trained actor, role player, volunteer, or other person engaged to portray a disaster victim during emergency drills to train first resp...

 

 

Football Club Forlì 2012-2013

Voce principale: Football Club Forlì. Football Club ForlìStagione 2012-2013Sport calcio Squadra Forlì Allenatore Bardi Attilio Presidente Conficconi Romano Lega Pro Seconda Divisione 2012-20139º posto nel girone A Coppa Italia Lega Pro1° turno ad eliminazione Maggiori presenzeCampionato: P. Ginestra (32) Miglior marcatoreCampionato: Petrașcu (14) StadioTullo Morgagni Football Club Forlì 2011-2012 Football Club Forlì 2013-2014 Si invita a seguire il modello di voce Questa voce ra...

 

 

Zubair bin Awwam

Az-Zubair bin Al-‘AwwamLahir594MekkahMeninggal656BasraPengabdian Kekhalifahan Rasyidin.Dinas/cabang Pasukan RasyidinLama dinas636, 640-642PangkatKomandanKomandanPenaklukan Muslim di Mesir, Perang Saudara Az-Zubair bin Al-‘Awwam[1] (Arab: الزبير بن العوامcode: ar is deprecated ) (wafat 36 H/656 M) adalah putra bibi Muhammad, yaitu Shafiyyah binti Abdul Muthalib, yang juga salah satu sahabat nabi dan termasuk as-Sabiqun al-Awwalun (10 orang yang pertama masuk Isla...

Antoine Brutus Menier

Potret Jean-Antoine-Brutus Menier (1795-1853). Jean Antoine Brutus Menier (Bourgueil, 17 Mei 1795-Passy, 19 Desember 1853) adalah seorang industrialis Prancis, apoteker lulus pada usia 44 tahun, anggota keluarga chocolatier Menier dan pendiri perusahaan dengan nama yang sama pada 1816. Biografi Pabrik di Noisiel (ilustrasi dari publikasi Swedia pada 1880 atau 1890-an). Ia dididik di sekolah menengah La Flèche, di Sarthe, yang baru saja diubah menjadi prytanée militaire pada 1808. Apoteker L...

 

 

The Journal of Philosophy

Academic journalThe Journal of PhilosophyDisciplinePhilosophyLanguageEnglishEdited byThe Columbia University Department of PhilosophyPublication detailsHistory1921–present; 1904–1920 as The Journal of Philosophy, Psychology and Scientific MethodsPublisherThe Journal of Philosophy, Inc. (United States)FrequencyMonthlyStandard abbreviationsISO 4 (alt) · Bluebook (alt1 · alt2)NLM (alt) · MathSciNet (alt )ISO 4J. Philos.IndexingCODEN (alt...

 

 

コルク

この記事は検証可能な参考文献や出典が全く示されていないか、不十分です。出典を追加して記事の信頼性向上にご協力ください。（このテンプレートの使い方）出典検索?: コルク – ニュース · 書籍 · スカラー · CiNii · J-STAGE · NDL · dlib.jp · ジャパンサーチ · TWL（2017年4月） コルクを打ち抜いて作った瓶の栓 コルク（木栓、�...

Barry Sonnenfeld

Questa voce o sezione sugli argomenti professionisti cinematografici e registi statunitensi non cita le fonti necessarie o quelle presenti sono insufficienti. Puoi migliorare questa voce aggiungendo citazioni da fonti attendibili secondo le linee guida sull'uso delle fonti. Segui i suggerimenti dei progetti di riferimento 1, 2. Questa voce sugli argomenti direttori della fotografia statunitensi e registi statunitensi è solo un abbozzo. Contribuisci a migliorarla secondo le convenz...

 

 

Данио-рерио

Данио-рерио Научная классификация Домен:ЭукариотыЦарство:ЖивотныеПодцарство:ЭуметазоиБез ранга:Двусторонне-симметричныеБез ранга:ВторичноротыеТип:ХордовыеПодтип:ПозвоночныеИнфратип:ЧелюстноротыеГруппа:Костные рыбыКласс:Лучепёрые рыбыПодкласс:Новопёрые рыбыИн�...

 

 

Peristeri

For other uses, see Peristeri (disambiguation). Municipality in GreecePeristeri ΠεριστέριMunicipalityPeristeriLocation within the region Coordinates: 38°1′N 23°41′E / 38.017°N 23.683°E / 38.017; 23.683CountryGreeceAdministrative regionAtticaRegional unitWest AthensDistricts4Government • MayorAndreas Pachatouridis[1] (since 2003)Area • Municipality10.05 km2 (3.88 sq mi)Elevation50 m (160 ft)Popula...

Повітряні сили Збройних сил України

Ця стаття потребує додаткових посилань на джерела для поліпшення її перевірності. Будь ласка, допоможіть удосконалити цю статтю, додавши посилання на надійні (авторитетні) джерела. Зверніться на сторінку обговорення за поясненнями та допоможіть виправити недоліки. Мат...

 

 

李光耀之死

李光耀逝世及葬礼李光耀（1923年－2015年）日期2015年3月23日－2015年3月29日地点新加坡斯里淡马锡（私人守灵）新加坡国会大厦（民众瞻仰）新加坡国立大学文化中心（国葬）万礼火葬场（英语：Mandai Crematorium and Columbarium）（火葬）网站www.rememberingleekuanyew.sg 2015年3月23日凌晨3時18分（新加坡標準時間），新加坡建国后首任总理、前內閣资政和执政人民行动党首任秘书长李光�...

 

 

Cabinet Secretary for North Wales

Welsh Government cabinet minister Cabinet Secretary for North Wales of the Welsh GovernmentYsgrifennydd y Cabinet dros Ogledd Cymru (Welsh)IncumbentKen Skates MSsince 21 March 2024 (2024-03-21)Welsh GovernmentStyleWelsh MinisterStatusCabinet MinisterAbbreviationMinisterMember ofSeneddCabinetReports tothe Senedd and the First Minister of WalesSeatCardiffNominatorFirst Minister of WalesAppointerThe CrownTerm lengthFive yearsSubject to elections to the Senedd which take ...

The Shaggy Dog (franchise)

American media franchise The Shaggy DogLogo of 2006 filmBased onThe Hound of Florence: A Novelby Felix SaltenStarringVarious actors (See list below)Distributed byThe Walt Disney CompanyRelease date1959–presentCountryUnited StatesLanguageEnglishBudget>$60,125,000 (total of 2 films)Box office>$106,634,280 (total of 3 films)[a] The Shaggy Dog franchise consists of American science fiction-fantasy-comedy films, with three theatrical releases, and two made-for-television films. The...

 

 

Easter Rising

1916 armed insurrection in Ireland This article is about the armed insurrection in Ireland. For the musical, see Easter Rising (musical). Easter RisingÉirí Amach na CáscaPart of the Irish revolutionary periodO'Connell Street, Dublin, after the Rising. The GPO is at left, and Nelson's Pillar at right.Date24–29 April 1916LocationMostly Dublin; skirmishes in counties Meath, Galway, Louth, Wexford, CorkResult Unconditional surrender of rebel forces, execution of most leadersBelligerents Iris...

 

 

Pyramide de Djedkarê Isési

Si ce bandeau n'est plus pertinent, retirez-le. Cliquez ici pour en savoir plus. Cet article ne cite pas suffisamment ses sources (novembre 2022). Si vous disposez d'ouvrages ou d'articles de référence ou si vous connaissez des sites web de qualité traitant du thème abordé ici, merci de compléter l'article en donnant les références utiles à sa vérifiabilité et en les liant à la section « Notes et références ». En pratique : Quelles sources sont attendues ? ...

Patin siam

Patin (jambal) siam Patin siam Status konservasi NE[1] Klasifikasi ilmiah Kerajaan: Animalia Filum: Chordata Kelas: Actinopterygii Ordo: Siluriformes Famili: Pangasiidae Genus: Pangasianodon Spesies: P. hypophthalmus Nama binomial Pangasianodon hypophthalmusSauvage, 1878 Sinonim Pangasius sutchi Fowler, 1937[2] Patin siam (Pangasianodon hypophthalmus) adalah ikan budidaya dan akuarium yang populer. Ikan ini dikenal pula dengan nama jambal siam, lele bangkok, dan hiu bang...

 

 

サーフィン

この記事は検証可能な参考文献や出典が全く示されていないか、不十分です。 出典を追加して記事の信頼性向上にご協力ください。（このテンプレートの使い方）出典検索?: サーフィン – ニュース · 書籍 · スカラー · CiNii · J-STAGE · NDL · dlib.jp · ジャパンサーチ · TWL (2019年4月) サーフィンをする男性 サーフィン（英: surfin...