Reported morphology
Diamond / angular
Diamond, lozenge and sharply angular forms that do not fit the disc or triangle families.
Overview
Diamond-shaped reports are less common than disc or triangle descriptions. Their apparent geometry may depend strongly on viewing angle, especially when a three-dimensional object is reduced to a night-time silhouette.
Observation and identification
Descriptions of corners, edges and orientation should be traced to the earliest account. A later illustration can stabilise a geometry that the original testimony left uncertain.
The earliest wording, sketches and recordings carry greater evidential weight than later labels or illustrations.
Selected reports
These sources preserve the relevant shape description. Their provenance and limitations are noted in each summary.
The accompanying mission report described the UAP as diamond-shaped. AARO's video narrative instead compared the visible contrast area to an inverted teardrop with a trailing vertical mass, so the released record does not preserve one uncontested geometry.
Open record UK Ministry of Defence UFO Report 1997The log records diamond descriptions at Edinburgh on 7 May, Norwich on 30 June, North Weald on 5 August and the River Humber near Brough on 10 October. The Norwich entry allows either triangular or diamond form; all four remain brief intake summaries rather than validated geometries.
Open record UK Ministry of Defence UFO Report 1998The log records diamond descriptions at Halifax on 24 February, Barking on 13 July and Ventnor on 20 December. None of the short entries supplies the underlying observation material needed to reconstruct range or form.
Open recordNotable cases
The reported form is material to these cases; the links do not imply a common object or cause.
Comparison cases
These cases bear on perception, geometry or sensor interpretation but are not classified as examples of this form.
Public record
These pages document the institutional and historical record associated with the reports.
No dedicated UAPRAD public-record page has yet been assigned to this form. Relevant records will be added only where the morphology is material to the source.
Key witnesses
Each dossier separates direct observation from later recollection and interpretation.
Evidence assessment
Cash–Landrum provides a prominent diamond-form account, but one contested case cannot establish a wider class. Reported medical effects and the object’s alleged geometry are separate claims and require separate supporting evidence.
Source library
Sources are grouped by evidential role. A tier records provenance and directness; it does not determine whether a reported interpretation is correct.
Tier 2 Official and institutional records
- DOW-UAP-PR28, Unresolved UAP Report — A mission report used the term diamond-shaped, while AARO's imagery narrative described an inverted-teardrop appearance. The discrepancy is retained rather than resolved by the category label.
- UK Ministry of Defence UFO Report 1997 — Four dated entries use diamond language, including one that also allows a triangular description. The log records reports received and does not validate object identity or geometry.
- UK Ministry of Defence UFO Report 1998 — Three dated entries use diamond language; supporting investigation material is not supplied in the log.
