diff --git a/ext/SparseArraysExt.jl b/ext/SparseArraysExt.jl
index beab269ae..6ee5ca5bf 100644
--- a/ext/SparseArraysExt.jl
+++ b/ext/SparseArraysExt.jl
@@ -3,7 +3,7 @@ module SparseArraysExt
 using Finch
 using Finch: AbstractCompiler, DefaultStyle, Extent
 using Finch: Unfurled, Furlable, Stepper, Jumper, Run, Fill, Lookup, Simplify, Sequence, Phase, Thunk, Spike 
-using Finch: virtual_size, virtual_default, getstart, getstop, freshen
+using Finch: virtual_size, virtual_default, getstart, getstop, freshen, SwizzleArray
 using Finch.FinchNotation
 
 using Base: @kwdef
@@ -34,6 +34,36 @@ function Finch.fiber!(arr::SparseVector{Tv, Ti}; default=zero(Tv)) where {Tv, Ti
     return Fiber(SparseList{Ti}(Element{zero(Tv)}(arr.nzval), n, [1, length(arr.nzind) + 1], arr.nzind))
 end
 
+"""
+    SparseMatrixCSC(arr::Union{Fiber, SwizzleArray})
+
+Construct a sparse matrix from a fiber or swizzle. May reuse the underlying storage if possible.
+"""
+function SparseArrays.SparseMatrixCSC(arr::Union{Fiber, SwizzleArray})
+    default(arr) === zero(eltype(arr)) || throw(ArgumentError("SparseArrays, a Julia stdlib, only supports zero default values, was given $(default(arr)) as default"))
+    return SparseMatrixCSC(Fiber!(Dense(SparseList(Element(0.0))), arr))
+end
+
+function SparseArrays.SparseMatrixCSC(arr::Fiber{<:Dense{Ti, <:SparseList{Ti, Ptr, Idx, <:Element{D, Tv}}}}) where {D, Ti, Ptr, Idx, Tv}
+    D === zero(Tv) || throw(ArgumentError("SparseArrays, a Julia stdlib, only supports zero default values, was given $D as default"))
+    return SparseMatrixCSC{Tv, Ti}(size(arr)..., arr.lvl.lvl.ptr, arr.lvl.lvl.idx, arr.lvl.lvl.lvl.val)
+end
+
+"""
+    sparse(arr::Union{Fiber, SwizzleArray})
+
+Construct a SparseArray from a Fiber or Swizzle. May reuse the underlying storage if possible.
+"""
+function SparseArrays.sparse(fbr::Union{Fiber, SwizzleArray})
+    if ndims(fbr) == 1
+        return SparseVector(fbr)
+    elseif ndims(fbr) == 2
+        return SparseMatrixCSC(fbr)
+    else
+        throw(ArgumentError("SparseArrays, a Julia stdlib, only supports 1-D and 2-D arrays, was given a $(ndims(fbr))-D array"))
+    end
+end
+
 @kwdef mutable struct VirtualSparseMatrixCSC
     ex
     Tv
@@ -131,6 +161,20 @@ Finch.FinchNotation.finch_leaf(x::VirtualSparseMatrixCSC) = virtual(x)
 Finch.virtual_default(arr::VirtualSparseMatrixCSC, ctx) = zero(arr.Tv)
 Finch.virtual_eltype(tns::VirtualSparseMatrixCSC, ctx) = tns.Tv
 
+"""
+    SparseVector(arr::Union{Fiber, SwizzleArray})
+
+Construct a sparse matrix from a fiber or swizzle. May reuse the underlying storage if possible.
+"""
+function SparseArrays.SparseVector(arr::Union{Fiber, SwizzleArray})
+    default(arr) === zero(eltype(arr)) || throw(ArgumentError("SparseArrays, a Julia stdlib, only supports zero default values, was given $(default(arr)) as default"))
+    return SparseVector(Fiber!(SparseList(Element(0.0)), arr))
+end
+
+function SparseArrays.SparseVector(arr::Fiber{<:SparseList{Ti, Ptr, Idx, <:Element{D, Tv}}}) where {Ti, Ptr, Idx, Tv, D}
+    D === zero(Tv) || throw(ArgumentError("SparseArrays, a Julia stdlib, only supports zero default values, was given $D as default"))
+    return SparseVector{Tv, Ti}(size(arr)..., arr.lvl.idx, arr.lvl.lvl.val)
+end
 @kwdef mutable struct VirtualSparseVector
     ex
     Tv
diff --git a/src/interface/abstractarrays.jl b/src/interface/abstractarrays.jl
index 854141222..e020f9418 100644
--- a/src/interface/abstractarrays.jl
+++ b/src/interface/abstractarrays.jl
@@ -53,6 +53,16 @@ end
 default(a::AbstractArray) = default(typeof(a))
 default(T::Type{<:AbstractArray}) = zero(eltype(T))
 
+"""
+    Array(arr::Union{Fiber, SwizzleArray})
+
+Construct an array from a fiber or swizzle. May reuse memory, will usually densify the fiber.
+"""
+function Base.Array(fbr::Union{Fiber, SwizzleArray})
+    arr = Array{eltype(fbr)}(undef, size(fbr)...)
+    return copyto!(arr, fbr)
+end
+
 struct AsArray{T, N, Fbr} <: AbstractArray{T, N}
     fbr::Fbr
     function AsArray{T, N, Fbr}(fbr::Fbr) where {T, N, Fbr}
diff --git a/test/test_issues.jl b/test/test_issues.jl
index 44f96b3bc..b22f6ff54 100644
--- a/test/test_issues.jl
+++ b/test/test_issues.jl
@@ -489,4 +489,26 @@ using CIndices
 
         @finch (output_tensor .=0; for j=_,i=_,k=_; output_tensor[i,k] += a_fiber[i,j] * b_fiber[k,j]; end)
     end
+
+    #https://github.com/willow-ahrens/Finch.jl/issues/321
+    let
+        A = fsprand((10, 10), 0.1)
+        B = sparse(A)
+        @test B isa SparseMatrixCSC
+        @test B == A
+        B = SparseMatrixCSC(A)
+        @test B isa SparseMatrixCSC
+        @test B == A
+        A = fsprand((10,), 0.1)
+        B = sparse(A)
+        @test B isa SparseVector
+        @test B == A
+        B = SparseVector(A)
+        @test B isa SparseVector
+        @test B == A
+        A = fsprand((10, 10), 0.1)
+        B = Array(A)
+        @test B isa Array
+        @test B == A
+    end
 end