Tesbihkâr

Oltu stone

3 usages
Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.trOltu taşıarحجر أولتو

Short answer

A black, matte, light stone quarried around Oltu near Erzurum, recorded as “Oltu stone” as a bead material. The recorded usages link it to the jet class of the international literature; the peer-reviewed literature calls it a “semi-precious coaly stone”, and whether it is classified as jet or as lignite varies by source. Its Turkish dictionary equivalent is “black amber” — the name is a simile: Oltu stone is not a resin but a coal of plant origin.

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Tests you can do at home: Transmitted light · Hydrostatic specific gravity · Simichrome test (may leave a mark on the surface; try it only on a hidden spot)

Meanings in the trade

These are the recorded usages of the term: publications, catalogues and the market. Each usage carries its own source grade and is not a definition.

  • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.BookJet
    Malzeme maddesi 'Oltu Taşı' (s.35): siyah, Erzurum çevresi; katalog 12 (s.76).
  • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.OtherJet
    Oltu taşı, Latince adı 'Jayet' olan ve uluslararası literatürde 'jet' olarak bilinen mineraloid sınıfına girer; Orta Çağ'dan beri tespih yapımında kullanılır.
  • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Dealer siteJet
    MENSEI: ERZURUM EL ISCILIGI ERZURUM OLTU TASI MALZEME

Canonical mapping

A mapping is not a conclusion: it is a claim about what the term points to, not a measurement of the material.

Oltu stoneJet

How to tell — and what it does not tell

This text has so far been written only in Turkish; the text you see is in Turkish.

How to tell

  • Specific gravity Jetin özgül ağırlığı için O'Donoghue 2006 tanımlama tablosu 'genellikle 1,20–1,30' verir; Phu Quoc (Vietnam) jetinde altı örnekte ölçülen değerler 1,21–1,25'tir (Le Ngoc Nang ve ark. 2022). Pres Oltu taşı için 1,22–1,26 bildirilmiştir (Bawani ve ark. 2023). Bu değerlerle jet doygun tuzlu suda yüzebilir; 1,30–1,35 alt ucu her jet için geçerli değildir.

    • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Gems: Their Sources, Descriptions and Identification, 6th ed.O'Donoghue, M. (ed.)2006
      usually 1.20 to 1.30

      Accessed on:

    • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Characteristics of Jet in Phu Quoc island, Kien Giang province, Viet NamLe Ngoc Nang et al.2022
      SGs recorded for six samples were 1.21, 1.25, and 1.24

      Accessed on:

    • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Conversion of cleaned Oltu-stone wastes ... binderless agglomerationBawani, M. R. et al.2023
      bulk density of pressed Oltu-stone was reported to be 1.22-1.26

      Accessed on:

    • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Evaluation of Turkish black amber: A case study of OltuKalkan, E. et al.2012
      Specific gravity 1.26

      Accessed on:

    • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Jetgemdat
      1.19 to 1.35

      Accessed on:

History and names

  • Trade-name history

  • Production period Oltu taşı Orta Çağ'da tesbih, kutsal sayılan sandık ve heykel yapımında kullanılırken XIX. yüzyılda mücevher yapımına da girdi.

    • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Oltu taşıVikipedi (TR)
      Orta Çağlarda tespih, kutsal sayılan sandık ve heykel yapımında kullanılmaktayken, XIX. yüzyılda mücevher yapımında da kullanılmaya başlanmıştır

      Accessed on:

Show all (3)

  • Specific gravity Oltu taşı (jet) bağıl yoğunluğu 1,3-1,4; Mohs sertliği 2,5-4,0.

    • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Oltu taşıVikipedi (TR)
      1,3–1,4 bağıl yoğunluğa ve 2,5–4,0 Mohs sertliğine sahiptir

      Accessed on:

  • Specific gravity

    • Evidence grade D — listing, forum, social media. The grade states the type of the source, not the truth of the claim.Oltu Taşı - Jet - Siyah Kehribar Özellikleridegerlitaslar.gen.tr
      Oltu taşının yoğunluğu yaklaşık 1,30-1,34 g/cm3 ... Mohs sertliği 2,5-3

      Accessed on:

  • Other Oltu taşı bir ağaç türünün gövdesinin fosilleşmiş halidir; uluslararası literatürde 'jet' olarak bilinen mineraloid sınıfındadır. Açık havaya çıktığında yumuşak yapısından sertleşme gösterir — işleme sırası üzerinde etkisi vardır.

    • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Oltu taşıVikipedi (TR)
      bir ağaç türünün gövdesinin fosilleşmiş halidir

      Accessed on:

Sources

A grade states the strength of the source, not of the conclusion.

Recorded usages: 3Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.

  • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Sabırla Selamete Tane Tane… Osmanlı Kültüründe Tesbih ve Hüsnü Dikeçligil Tesbih KoleksiyonuTekin, Kemal Hakan2014ISBN 978-605-65152-0-0 s.35

    Accessed on:

  • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Sabırla Selamete Tane Tane… Osmanlı Kültüründe Tesbih ve Hüsnü Dikeçligil Tesbih KoleksiyonuTekin, Kemal Hakan2014ISBN 978-605-65152-0-0 s.76

    Accessed on:

  • Evidence grade B — auction or explicit attribution. The grade states the type of the source, not the truth of the claim.TDK Güncel Türkçe Sözlük — Oltu taşı

    Accessed on:

  • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Petrographical properties of a semi-precious coaly stone, Oltu stone, from eastern TurkeyToprak, S.2013

    Accessed on:

  • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Fitolojik Kökenli Bir Fosil: OLTU TAŞIDoğanay, Hayati
    kalori değeri düşük taşkömürlerine yakın bir linyit kömürü türüdür

    Accessed on:

  • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Gems: Their Sources, Descriptions and Identification, 6th ed.O'Donoghue, M. (ed.)2006
    usually 1.20 to 1.30

    Accessed on:

  • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Characteristics of Jet in Phu Quoc island, Kien Giang province, Viet NamLe Ngoc Nang et al.2022
    SGs recorded for six samples were 1.21, 1.25, and 1.24

    Accessed on:

  • Evidence grade A — publication. The grade states the type of the source, not the truth of the claim.Conversion of cleaned Oltu-stone wastes ... binderless agglomerationBawani, M. R. et al.2023
    bulk density of pressed Oltu-stone was reported to be 1.22-1.26

    Accessed on:

  • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Evaluation of Turkish black amber: A case study of OltuKalkan, E. et al.2012
    Specific gravity 1.26

    Accessed on:

  • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Jetgemdat
    1.19 to 1.35

    Accessed on:

  • Evidence grade C — institutional seller. The grade states the type of the source, not the truth of the claim.Oltu taşıVikipedi (TR)
    1,3–1,4 bağıl yoğunluğa ve 2,5–4,0 Mohs sertliğine sahiptir

    Accessed on:

  • Evidence grade D — listing, forum, social media. The grade states the type of the source, not the truth of the claim.Oltu Taşı - Jet - Siyah Kehribar Özellikleridegerlitaslar.gen.tr
    Oltu taşının yoğunluğu yaklaşık 1,30-1,34 g/cm3 ... Mohs sertliği 2,5-3

    Accessed on:

Oltu stone · Tesbihkâr