1971 - Lanka
Ten Cents - TRIAL
A set of TRIAL patterns were struck with date 1971 to select a cheaper alloy
for the Five cents and Ten cents coins
in which the Nickel-Brass metal had become almost half the face-value.
Patterns were struck for both Five cents
and Ten cents denominations in Nickel-Brass clad steel, Chromized
steel and Aluminum with word TRIAL in raised letters on Obverse.
Rare 1975 Aluminum off-metal-strikes (OMS) also exist for both Five cents and
Ten cents.
Aluminum was adopted and made legal for the Five and Ten cents coins
from the 1978 issue.
Aluminum had been used for the one and two cents coins since 1963.
| SPECIFICATIONS |
| Denomination | Ten cents |
| Alloy | Nickel-Brass clad Steel |
| Diameter | 23.11/20.96 mm |
| Thickness | 1.55 mm |
| Weight | 4.04 gms |
| Shape | eight scallops |
| Edge | Plain Steel |
| Die-Axis | 0° |
|
|
|
| KM unlisted |
| Denomination | Ten cents |
| Alloy | Chromized Steel |
| Diameter | 23.11/20.96 mm |
| Thickness | 1.41 mm |
| Weight | 3.69 gms |
| Shape | eight scallops |
| Edge | Plain |
| Die-Axis | 0° |
|
|
|
| KM Unlisted |
| Denomination | Ten cents |
| Alloy | Aluminum |
| Diameter | 23.11/20.96 mm |
| Thickness | 1.55 mm |
| Weight | 1.30 gms |
| Shape | eight scallops |
| Edge | Plain |
| Die-Axis | 0° |
|
|
|
| KM unlisted |
Obverse : The Armorial Ensign of Ceylon with
இலங்கை in Thamil on left,
ලංකා in Sinhala in middle,
and CEYLON on left in a scroll at its bottom. All within circle of radial dashes along periphery with raised rim.
Word TRIAL to the right and upper side (2 O'Clock).
Reverse : The large numeral denomination 10 with big
සත දහය in Sinhala,
and smaller
பத்து சதம் in Thamil
and TEN CENTS below and year of issue at the bottom,
with traditional Sinhala Liyavela art on either side, and country name
ලංකා (Lanka)
in Sinhala centered on top. All within circle of radial dashes along periphery with raised rim.
Considering the weight, thickness and edge of the coins it appears that the
Steel core of the Nickel-Brass Clad pattern is similer to the Chromized
Steel pattern.
Qualitative x-ray floresence spectra show the clear presence of
Chromium with the Iron in the Chromized Steel TRIAL. NO trace
of Chromium was detected on exposed Steel core along the edge of the
Nickel-Brass Clad TRIAL. No Iron was detected on surface of same coin
indicating a thick clad of Nickel-Brass.
I have seen 2+5/6 sets of these TRIAL coins.
I am seeking information about other sets of these Pattern.
I am not sure how many were produced or known to exist.
Retired officer T. M. U. Sallay of the Central Bank of Ceylon,
confirmed them to be official Patterns.
There is also a 1965
Ten Cents with word TRIAL
in raised letters on both Reverse (10 O'clock) and on Obverse (9 O'clock).
It is non-magnetic and of the same weight and metal as the standard issue
of that year. It was struck most probably in Birmingham Mint when they
got the subcontract from the British Royal Mint (BRM) which first struck
it few years previously in 1963.
The TRIAL coins were scanned at 600dpi and the images are displayed at 250dpi.
There appears to be slight corrosion on the obverse of Aluminum specimen
imaged due probably to poor storage.