platinum

American  

[plat-n-uhm, plat-nuhm] / ˈplæt n əm, ˈplæt nəm /

noun

1. Chemistry. a heavy, grayish-white, highly malleable and ductile metallic element, resistant to most chemicals, practically unoxidizable except in the presence of bases, and fusible only at extremely high temperatures: used for making chemical and scientific apparatus, as a catalyst in the oxidation of ammonia to nitric acid, and in jewelry. Pt; 195.09; 78; 21.5 at 20°C.

2. a light, metallic gray with very slight bluish tinge when compared with silver.

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adjective

1. made of platinum.

2. (of an audio recording) having sold a minimum of one million copies.

platinum British  

/ ˈplætɪnəm /

noun

1. a ductile malleable silvery-white metallic element, very resistant to heat and chemicals. It occurs free and in association with other platinum metals, esp in osmiridium: used in jewellery, laboratory apparatus, electrical contacts, dentistry, electroplating, and as a catalyst. Symbol: Pt; atomic no: 78; atomic wt: 195.08; valency: 1–4; relative density: 21.45; melting pt: 1769°C; boiling pt: 3827±100°C

2. 1. a medium to light grey colour

   2. ( as adjective )

      a platinum carpet

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platinum Scientific  

/ plăt′n-əm /

1. A soft, ductile, malleable, silver-white metallic element that usually occurs with osmium, iridium, palladium, or nickel. It has a high melting point and does not corrode in air. Platinum is used as a catalyst and in making jewelry, electrical contacts, and dental crowns. Atomic number 78; atomic weight 195.08; melting point 1,772°C; boiling point 3,827°C; specific gravity 21.45; valence 2, 3, 4.

2. See Periodic Table

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Etymology

Origin of platinum

1805–15; < New Latin, alteration of earlier platina < Spanish; platina

Example Sentences

Additionally, the moon is home to water ice, which can be used for rocket propulsion, as well as rare earth minerals such as lithium, platinum and other materials critical to electronics and clean energy technology.

From BBC

Catalytic converters need rare elements like palladium and platinum, precious metals more at home in a jewelry box than in a car.

From Los Angeles Times

However, it expects gold, silver and platinum to recover strongly as the energy shock wanes later in the year.

From The Wall Street Journal

The top 20% of companies for each group were awarded a platinum designation, while the next 20% got a gold status.

From The Wall Street Journal

They were winding up the holiday when his platinum ring slipped off his finger.

From The Wall Street Journal

Related Words

• gold
• iron
• metal
• mineral