pseudomorph

[soo-duh-mawrf]

noun

1. an irregular or unclassifiable form.

2. a mineral having the outward appearance of another mineral that it has replaced by chemical action.

pseudomorph

/ ˈsjuːdəʊˌmɔːf /

noun

1. a mineral that has an uncharacteristic crystalline form as a result of assuming the shape of another mineral that it has replaced

Other Word Forms

• pseudomorphic adjective
• pseudomorphous adjective
• pseudomorphism noun

Word History and Origins

Origin of pseudomorph¹

First recorded in 1840–50; pseudo- + -morph

Example Sentences

It is a pseudomorph after iolite, and consists mainly of hydrous aluminium silicate.

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Cassiterite occurs as a pseudomorph after orthoclase felspar in some of the altered granite of Cornwall, and it has occasionally been found as a cementing material in certain brecciated lodes.

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The secondary mineral begins to form upon the surfaces and along the cracks of the olivine, gradually producing a mesh-work in the interstices of which small kernels of olivine remain; and when the process is completed the mesh structure persists in the resulting pseudomorph, giving a clear indication as to its history.

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It is then called a pseudomorph, which is a term applied to any mineral which, instead of having the form it should possess, shows the form of something which has altered its structure completely, and then disappeared.

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Hawksnest, over beyond, I noted, had its pseudomorph too; a newspaper proprietor of the type that hustles along with stolen ideas from one loud sink-or-swim enterprise to another, had bought the place outright; Redgrave was in the hands of brewers.

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