View source for Bort

{{Short description|Shards of non-gem-quality diamonds}}
{{About|the mineral or gem}}
{{Redirect|Boart|the mineral exploration company|Boart Longyear}}
{{Infobox mineral
| name        = Bort<br /><small>(also ''boort'' or ''boart'')</small>
| image       = File:Diamond-270244.jpg
| imagesize   = <!-- 260px -->
| alt         = mixed clump of both gem and non-gem grade (bort) particles
| caption     = A mixture of bort and gem diamonds {{nowrap|(larger inclusions)}} from the {{nowrap|[[Crater of Diamonds State Park]]}}
| category    = [[Mineral]] variety
| formula     = C
| molweight   =
| strunz      =
| dana        =
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| unit cell   =
| color       = Varies (white to yellowish in powder form, yellow to brownish in larger shards)
| colour      =
| habit       = 
| twinning    =
| cleavage    = 
| fracture    = 
| tenacity    = 
| mohs        = 
| luster      = 
| streak      = 
| diaphaneity = 
| gravity     = 
| density     =
| polish      =
| opticalprop = 
| refractive  = 
| birefringence =
| pleochroism = 
| 2V          =
| dispersion  = 
| extinction  =
| length fast/slow =
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| absorption  =
| melt        = 
| fusibility  =
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| impurities  =
| alteration  =
| var1        = Similar occurrences
| var1text    = 
{{bulletedlist
| [[Diamond]]
| [[Ballas]]
| [[Graphite]]
| [[Carbon]]
| [[Carbonado (diamond)|Carbonado]]
| [[Coal]]
}}
| prop1       = Use/purpose
| prop1text   = 
{{bulletedlist
| [[Diamond industry]]
| [[Abrasive]]
| [[Polishing]]
| [[Lubricant]] (as [[oil additive]])
}}
| var2        = 
| var2text    = 
| references  =
}}

'''Bort''', '''boart''', or '''boort''' is an [[umbrella term]] used in the [[diamond]] industry to refer to shards of non-[[gemstone|gem]]-grade/quality diamonds. In the manufacturing and heavy industries, "bort" is used to describe dark, imperfectly formed or crystallized diamonds of varying levels of opacity. The word is ultimately [[Dutch language|Dutch]] and is related to the English term for drilling, ''to bore''.<ref>{{Citation |title=bort |date=2025-02-02 |publisher=Wiktionary, the free dictionary |url=https://en.wiktionary.org/wiki/bor |access-date=2025-04-24 |language=en}}</ref> The lowest grade, "crushing bort", is crushed by steel [[mortar and pestle|mortars]] and used to make industrial-grade [[abrasive]] grits. Small bort crystals are used in [[drill bit]]s. The [[Democratic Republic of the Congo]] provides 75% of the world supply of crushing bort.<ref name="Spear" /><ref name="Brit_1" /><ref name="Brit_2" />

== Use and application ==
Bort is commonly used as an [[abrasive]]. Smaller flakes and particles are used as an additive for scouring or polishing pastes and agents. Larger particles can be added to cutting, drilling and grinding tools to improve their lifespan and substantially increase their efficiency.<ref name="usage_1" />

Bort particles varying from one to two [[nanometer]]s<ref name="sn-1" /> are added to [[lubricant]]s such as [[Mineral oil|paraffin oil]]. These particles will embed themselves into minute irregularities and imperfections of moving-part surfaces. Particles that remain [[Suspension (chemistry)|suspended]] in the lubricant oil act as both a polishing agent, further smoothening the surfaces, and as [[ball bearing]]s between the surfaces. Such [[nanotechnology]] applications with paraffin oil containing approximately 1% of these nano-size bort particles may decrease the [[friction]] up to half of that without the nano-particles.<ref name="aiche.org-1" /><ref name="nrc.nl-1" />

<gallery widths=200 heights=160>
File:Diamant.jpg|Bort-like heavily [[Crystal twinning|twinned]] diamond from Congo
File:Necklace made of rough diamonds.jpg|Necklace made of cut-off chips and low-quality rough diamonds
</gallery>

== See also ==
{{Portal|Geology|Minerals}}
* [[Ballas]]
* [[Carbonado]] (black diamond)
* [[Rough diamond]]
* [[Synthetic diamond]]

== References ==
{{Reflist|refs=
<ref name="Spear">{{cite book |last1= Spear |first1= K.E |last2= Dismukes |first2= J.P. |title= Synthetic Diamond: Emerging CVD Science and Technology |url= https://books.google.com/books?id=RR5HF25DB7UC |page= 628 |publisher= [[John Wiley & Sons|Wiley]]–[[IEEE]] |year= 1994 |isbn= 0-471-53589-3 |url-status= live |archiveurl= https://web.archive.org/web/20150425115752/http://books.google.com/books?id=RR5HF25DB7UC |archivedate= 2015-04-25 }}</ref>
<ref name="Brit_1">"[http://www.britannica.com/EBchecked/topic/287017/industrial-diamond?anchor=ref71892 Industrial diamond]". ''[[Encyclopædia Britannica]]''.</ref>
<ref name="Brit_2">"[https://www.britannica.com/topic/bort Bort]". ''[[Encyclopædia Britannica]]''.</ref>
<ref name="usage_1">{{Cite book | publisher=Mines Bureau | url= https://books.google.com/books?id=zyKCNW0BHm8C&q=use+of+bort+as+abrasive+polisher+and+on+drilling+and+sawing+tools&pg=SA21-PA2 | title= Minerals Yearbook Metals and Minerals 2010 Volume I | pages= 21–22 | date= 2010 | accessdate=December 30, 2018 | isbn= 978-1-4113-3449-6 | archivedate= December 30, 2018 | archiveurl= https://web.archive.org/web/20181230142508/https://books.google.nl/books?id=zyKCNW0BHm8C&pg=SA21-PA2&lpg=SA21-PA2&dq=use+of+bort+as+abrasive+polisher+and+on+drilling+and+sawing+tools&source=bl&ots=gyGJyiwFeY&sig=qfnq6I08pJFifL8bGZ08jsMgLs4&hl=en&sa=X&ved=2ahUKEwjcruDt3cffAhWKbVAKHYgoDFMQ6AEwDXoECAcQAQ | url-status= live }}</ref>
<ref name="aiche.org-1">{{cite web | first= Jason | last= Ballengee | url= https://www.aiche.org/sites/default/files/community/258271/aiche-community-site-page/258701/january-aichepresentation-pdf.pdf | date= 2016 | title= Nanodiamond and Lubrication Applications | website= aiche.org | publisher= SP3 NANOTECH, LLC | archiveurl= https://web.archive.org/web/20181206102553/https://www.aiche.org/sites/default/files/community/258271/aiche-community-site-page/258701/january-aichepresentation-pdf.pdf | archivedate= December 6, 2018 | access-date= December 6, 2018 | url-status= live }}</ref>
<ref name="sn-1">[[Scientific notation]] in [[SI unit]](s): 1–2 × 10<sup>−9</sup> m.</ref>
<ref name="nrc.nl-1"><!-- /* Additional source  mainly with regards to the claim of 50% decrease of friction, however, in Dutch; might benefit by source supporting the same claim in the English language */ -->{{Cite news |last=Beekman |first=George |url= https://www.nrc.nl/nieuws/1997/01/04/betere-smering-met-behulp-van-zeer-fijn-diamantpoeder-7337586-a498147 | title= Betere smering met behulp van zeer fijn diamantpoeder |trans-title=Better lubrication using diamond powder of very small particles | lang= Dutch | website= nrc.nl | publisher= [[NRC Handelsblad]] | date= January 6, 1997 | access-date= December 6, 2018 | archivedate= December 6, 2018 | archiveurl= https://web.archive.org/web/20181206093103/https://www.nrc.nl/nieuws/1997/01/04/betere-smering-met-behulp-van-zeer-fijn-diamantpoeder-7337586-a498147 | url-status= live }}</ref>
}}

== External links ==
{{EB1911 poster|Bort}}
* {{Wiktionary-inline}}

[[Category:Diamond]]