diff --git a/src/typed_particles.jl b/src/typed_particles.jl
index 0fd8cc0..76a819d 100644
--- a/src/typed_particles.jl
+++ b/src/typed_particles.jl
@@ -31,6 +31,7 @@ struct SParticle{z,Z,A} <: AbstractParticle
 end
 
 SParticle(z, Z, A) = SParticle{z,Z,A}()
+SParticle(p::AbstractParticle) = SParticle(charge_number(p), atomic_number(p), mass_number(p))
 
 # Basic properties - use single type parameter where possible
 charge_number(::SParticle{z}) where {z} = z
diff --git a/test/typed_particles.jl b/test/typed_particles.jl
index d4e3fef..0603719 100644
--- a/test/typed_particles.jl
+++ b/test/typed_particles.jl
@@ -5,9 +5,19 @@ using Test, ChargedParticles, Unitful
     p = SParticle(1, 2, 3)
     @test p isa AbstractParticle
     @test p isa SParticle{1,2,3}
+    @test p isa SParticle{1}
 
     # Test basic properties
     @test charge_number(p) == 1
     @test atomic_number(p) == 2
     @test mass_number(p) == 3
-end
\ No newline at end of file
+end
+
+@testset "SParticle and Particle" begin
+    p1 = Particle(:He, 1, 3)
+    p2 = SParticle(1, 2, 3)
+    p3 = SParticle(p1)
+    p4 = Particle(p2)
+    @test p3 == p2 != p1 == p4
+    @test string(p1) == string(p2)
+end