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.

---

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

---

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

---

Etymology

Origin of platinum

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

Example Sentences

Another major focus is reducing reliance on iridium, a costly platinum group metal used in PEM electrolysis.

From Science Daily

Throughout his career, the artist accumulated more than 40 productions, 30 million copies sold, 15 gold records, five platinum records, and 10 Grammy nominations.

From BBC

Their team – all dressed in tasselled cowboy outfits – have nabbed the prize for best-dressed, tying with another team decked out in pink nighties and platinum blonde wigs.

From BBC

During her training sessions, there was an easily recognizable shock of platinum blonde curls at the boards.

From The Wall Street Journal

Dead batteries yield lithium, cobalt and nickel; LED screens contain germanium; circuit boards hold platinum and palladium; hard disks store rare earths -- e‑waste has long been described as a "gold mine" for critical minerals.

From Barron's

Related Words

• gold
• iron
• metal
• mineral