Skip to main content

Table 1 Sample summary with information on crystalline silica features observed by Horwell et al. [12]

From: The structure of volcanic cristobalite in relation to its toxicity; relevance for the variable crystalline silica hazard

Sample No.

Date of collapse/eruption

Date of collection

Description

Eruption Information

Crystalline silica type

Prismatic

Platy

Devit. cristob.

Devit. quartz.

Dome rock:

MVO819

174 k.a. BP

15/2/98

Dome lava; very dense, grey/brown

Ancient sample from old complex

✓ but rare

✓

✓

✓

MVO945

400 a BP

?

Dome lava; Dense, red/brown

Ancient simple from Castle Peak

✓

×

×

✓

MVO287

21/9/97

21/9/97

Juvenile block; vesicular; light grey

From dome collapse deposit

✓

×

✓

×

MVO288

21/9/97

21/9/97

Juvenile block; frothy, light grey

From dome collapse deposit

✓ but rare

×

×

×

MVO617

21/9/97

16/5/98

Dome lava; Dense; Green/dark grey

From dome collapse deposit

✓

×

✓

×

MVO332

26/12/97

4/1/98

Dome lava; Vesicular; pale grey

From 'Boxing Day' collapse deposit

✓

×

×

×

MVO1236

12/7/03

1/8/03 – 15/11/03?

Dome lava; Dense; pale grey

From dome collapse deposit (full collapse)

✓

✓

✓

✓

MVO1406

20/5/06

?

Dome lava; dense; pale grey

From dome collapse deposit

✓

×

✓

×

MontR1*

20/5/06

22/6/06

Dome lava, dense, altered, red

From dome collapse deposit

✓

✓

×

✓

Ash:

MRA5/6/99

05/6/99

05/6/99

Co-PDC ash

Respirable (< 4 μm) fraction

 

MBA12/7/03

12/7/03

12/7/03

Co-PDC ash

Bulk ash from which cristobalite separated

 
  1. ‘Prismatic’ = euhedral cristobalite; ‘Platy’ = platelets of cristobalite; ‘Devit. cristob.’ = cristobalite during glass devitrification; ‘Devit. quartz’ = quartz formed (probably through phase transition from cristobalite) when the glass is totally devitrified.
  2. *Collected by BW from deposit rather than archive.
  3. MVO sample numbers assigned by the Montserrat Volcano Observatory.